Special features Contents Chapter 1 Algorithms 1 Chapter 2 Computer programming 17 Chapter 3 Data handling 42 Chapter 4 Information and communication technology 59 Let’s Play 75 Higher-order questions promote critical thinking skills. Collaborative activities encourage students to learn from each other and foster teamwork. More practices enable students to reinforce their understanding of the topic. Solving puzzles and brain-teasers helps to develop problem-solving skills and boost logical thinking. Video-based information engages viewers and enhances learning experience. Game-based learning incorporates problem solving and critical thinking skills. Extra relevant information helps in understanding the topic better. A summary helps students to identify the main ideas of the topic. ? ii Computing Science Primary 3
Chapter 1 Algorithms What will happen if you miss a step or jumble up the steps? If we missed a step or did not follow through the sequence correctly, we might end up in a mess and the rice might not cook properly. Every day our mother cooks rice. It is a simple daily task. However, it has many steps. What are algorithms? Step 1 Measure the rice and put it into the cooking pot. Step 2 Rinse the rice until the water turns clear. Step 5 Turn on the rice cooker. Step 6 When the rice is cooked, fluff the rice and serve. Step 3 Add water into the cooking pot. Step 4 Put the cooking pot into the rice cooker.
What are other activities or processes you have carried out that have a set of step-by-step instructions? What will happen if we do not follow the sequence? Will the results be the same? During a birthday party, the birthday girl or boy will blow the candles on the cake before serving the cake. There are steps to do so. There is a set of step-by-step instructions for every process or solution to a problem. This is known as an algorithm. In an algorithm, each step is identified and the order or sequence of the steps is determined. Could we carry out the above activity starting from step 5 instead of step 1? What would happen? 1 2 3 4 5 2 Computing Science Primary 3
Writing algorithms Actually, we have been exposed to algorithms in the earlier levels. When we listed out the solutions step by step either by writing, verbally or using symbols, we are actually performing algorithms. Let’s look at this example. Anong’s teacher asked Anong to determine if a number is an odd or even number. 75 An even number? An odd number? Anong wrote a simple reply algorithmically: So, is 75 an even number or an odd number? When 75 is divided by 2, the result is 37 with a remainder of 1. So, 75 is an odd number. If the number is divisible by 2 without any remainder, it is an even number. If the number is divisible by 2 with a remainder, it is an odd number. Chapter 1 3 Algorithms
How are we going to re-write the algorithm using symbols? 1 Do you still remember the meanings of these symbols? State their meanings. Symbol Meaning Start End Enter a number It is an even number. It is an odd number. Any remainder when divided by 2? No Yes 4 Computing Science Primary 3
Tic-tac-toe Tic-tac-toe is a fun game that is believed to exist for over 3,000 years ago. It is played on a grid of nine squares by two players. Firstly, we need to decide who starts the game. They will take turns to put a mark (either a X or an O) on the grid. The first player who gets 3 of his marks in a row wins. When all the squares are filled up and no one gets 3 marks in a row, the game ends in a tie. Now, below is an example of how this game is played. Player 1 Player 2 Player 1 Chapter 1 5 Algorithms
Player 2 Player 1 Player 1 Player 2 Player 2 Player 1 There are many options on where we can put the marks. Every different option produces different results. Let’s challenge ourselves. Can you win against the computer? http://tiny.cc/xyfofz In the second last step, what should Player 2 do in order not to lose but to end in a tie? Tips: Always try to figure out how to get 3 marks in a row. Always try to stop the opponent from getting 3 marks in a row. Always pay attention where the opponent puts his mark. 6 Computing Science Primary 3
The traditional tic-tac-toe is arranged in a 3-by-3 grid. Have you heard of tic-tac-toe arranged in a 4-by-4 grid? Find out more about it online. Nora has done an algorithm using symbols on how to play the game of tic-tac-toe. Analyze her algorithm. Is it correct? If not, rewrite the algorithm. 2 Start End Get X's move Get X's move Is X winning? Is O winning? Any more space? No No Yes Yes Yes No Chapter 1 7 Algorithms
1. An algorithm is a set of step-by-step instructions for every process or solution to a problem. 2. We can create algorithms either verbally, by writing or by using symbols. 3. We can use algorithms to guide others on how to play games, to reach a destination and even to solve a problem. 1. Here is a map of a mini zoo. Analyze it. ? RESTAURANT Elephant Tiger Seal Dolphin Giraffe Monkeys 14 Computing Science Primary 3
You plan to reach the zoo at 09.00 hours, watch each of these animal shows once which last for 20 minutes each: seal show at 09.15 hours, 12.15 hours and 14.15 hours elephant show at 09.45 hours, 11.45 hours and 14.45 hours dolphin show at 11.30 hours and 16.00 hours have lunch at the restaurant in the zoo, leave the zoo before 14.00 hours. You need to plan your route in the zoo. Make sure you are able to carry out all the activities planned. Describe your route below. Chapter 1 15 Algorithms
Play this snake-and-ladder game online. http://tiny.cc/gu6pfz 2. Have you played the snake-and-ladder game before? If not, play it online a few times first. Prepare an algorithm to guide a new player to play this game. 16 Computing Science Primary 3
Chapter 2 Computer programming Mimi’s class is going to have a class party. She decides to make 20 burgers. Her mother prepares the ingredients such as the... Her mother guides her on how to make a burger. Looping ...burger bread ...burger patties ...lettuce ...cheese
Mimi follows her mother’s guidance and makes 20 burgers. If you are going to instruct a robot to make 20 burgers, how are you going to write the program? Here are the steps to make a burger. Are you going to repeat writing these steps for another 19 times? End Take the bottom bun Add lettuce Add cheese Add a patty Add the top bun Start 18 Computing Science Primary 3
20 burgers? End Take the bottom bun Add the top bun Add lettuce Add cheese Add a patty Start Instead of writing the steps for 20 times, we can simplify the flow chart like this: A loop in a computer program is a set of instructions that repeats until a certain condition is met. In the example above, the condition is to make 20 burgers. Therefore, that set of instructions will be repeated until 20 burgers are made. What happens when 20 burgers are made in the example above? Yes No This is a loop. Chapter 2 19 Computer programming
If we are using the block-based software such as Code.org and Scratch, we can easily write the code as shown below. A car is at the side of a building as shown below. 1 1. Using the symbols below, program the car to move around the building and return to its original position. Building Move forward 1 box Turn right Turn left 20 Computing Science Primary 3
2. Guide the car to move around the building and return to its original position using a set of instructions in the form of flow chart. The first two instructions are done for you. Use a loop to simplify your chart. Move forward 2 boxes Start Chapter 2 21 Computer programming
3. Guide the car to move around the building and return to its original position by coding in a block-based software. Check with your friend who is sitting next to you. Is your instruction correct? Here are the steps to a simple dance using symbols. 2 5 11 1 6 7 8 9 10 12 13 14 15 16 17 2 3 4 18 19 20 21 22 Computing Science Primary 3
Do you notice that some parts are repeating? Identify them. The first few ones are done for you. These are the meanings of the symbols. Compare your results with your friends. Are they the same? If not, where did it go wrong? Move to the right. Move to the left. Snap your fingers. Laugh. Wave your hands in the air. Clap your hands. Stomp your feet. 4 times 3 times Chapter 2 23 Computer programming
Now, make a flow chart of the dance step. Cross-check with your friends if you have done it correctly. Start Clap your hands Stomp your feet Move to the right 4 times? 3 times? Yes Yes No No 24 Computing Science Primary 3
Explain how you did it. We can also do coding for the dance step. Below is the coding of the dance step in a block-based software. Complete it. Chapter 2 25 Computer programming
Simple coding Making sprites walk or run In Scratch, some sprites have more than one appearance. For example, the cat sprite has two appearances. Click on Costumes tab in the block palette. They are given different names, costume1 and costume2. We can use these two different appearances to make the cat sprite walk or run. Prepare the script as shown below. Two different appearances A note for teachers To download the Scratch software onto your computer, go to http://tiny.cc/lmcqfz for Windows operating system and http://tiny.cc/nscqfz for Macintosh operating system. Windows Mac Chapter 2 29 Computer programming
With the script above, the cat sprite walks only a few steps. How are we going to make it take more steps? Remember to change the appearance of the cat sprite in this block. Play the script. The legs of the cat sprite move but the cat does not change its position. The script below makes the cat sprite take a few steps forward. http://tiny.cc/dv4sfz http://tiny.cc/kz4sfz 30 Computing Science Primary 3
We can make the cat sprite run by reducing the waiting time. We can use the loop function to make the cat sprite repeat the walking action. We can change the number of times for the repetition of the action. Can we make the cat sprite run faster? How? http://tiny.cc/p54sfz http://tiny.cc/374sfz Chapter 2 31 Computer programming
Now, we want the cat sprite to walk to and fro between the edges of the stage. The cat sprite should bounce and walk in the opposite direction when it reaches the edge of the stage. If the cat sprite walks upside down after being bounced at the edge as shown, we need to change its rotation style. 32 Computing Science Primary 3
Changing sprites There are many different sprites that are available for immediate use. We can also draw, upload or even take a picture and use it as a sprite. Click on the head icon to choose a new sprite. Choose Bat1 and then click OK . Now, we have two sprites, the cat and the bat. We can easily delete a sprite by right-clicking the sprite in the sprite pane. Then, choose Delete . We can choose a sprite from the library. We can draw a sprite. We can upload a picture as a sprite. We can take a picture as a sprite. Chapter 2 33 Computer programming
Changing backdrops We can add and change the backdrop of the stage. Similarly, in sprites, we can choose a backdrop from the library. We can also draw, upload or take a picture to be used as the backdrop. Choose a new backdrop from the library. Try to delete it. Use your creativity to decorate the stage with an interesting backdrop image and sprites. 5 We can choose a backdrop from the library. We can draw a backdrop. We can upload a picture as a backdrop. We can take a picture as a backdrop. 34 Computing Science Primary 3
Work in pairs. You are required to make an animation of a hippopotamus flying to and fro in the blue sky with Scratch. Make sure it flies correctly. Write the script below. 6 Did you do it correctly? If not, debug it with your friends. http://tiny.cc/ib5sfz Chapter 2 35 Computer programming
Making sprites draw We can make sprites draw using the Pen block menu. Prepare the script as shown below. What did the cat do? Mimi wants the sprite to draw a square. However, her script is incorrect. Help Mimi to debug. 7 36 Computing Science Primary 3
How are we going to make the line to appear from the tip of the pencil? Choose the pencil sprite and make it draw a line. You will notice that the line does not appear drawn from the tip of the pencil, but from its center. Choose a pencil sprite. Select the Costumes tab in the block palette and then the Set costume center icon at the top right corner. Click at the tip of the pencil sprite. This will make the tip of the pencil sprite as its center. Try to draw lines with the pencil sprite. Chapter 2 37 Computer programming
8 Play your script. Does it give the same result? If not, try to debug your script. Work in pairs. Write a script that makes a starfish sprite in the sea swim in a triangular path. There is a line made by one of its tentacles while it swims. Discuss these points: How will you make the line appear from its tentacle? How will you make the sprite appear swimming? How will you determine the three points? http://tiny.cc/ae5sfz 38 Computing Science Primary 3
Aroon did a script to draw a simple staircase with 6 steps as shown. However, it did not turn out as it should be. Help him to debug. 9 You may ask a friend to help you to debug too. Besides the Repeat loop instruction block in Scratch, there are other kinds of loop instruction blocks such as the Forever loop, the If... then loop, If... then... else loop and the Repeat until... loop. Chapter 2 39 Computer programming
1. A loop in a computer program is a set of instructions that repeats until a specified condition is reached. ? Mali wants to instruct her toy airplane to fly to the airport through the maze. Identify the repeating actions. Circle them as a group. 1. Using the symbols below, guide her airplane to the airport. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Move to the right Move to the left Move up Move down 40 Computing Science Primary 3
2. Using the flow chart of symbols, guide the airplane to the airport. Remember to include looping to simplify the chart. 3. Prepare a script in Scratch to guide the airplane to the airport. Start Chapter 2 41 Computer programming
Chapter 3 Data handling Microsoft PowerPoint is a presentation graphic software. We can use it to create engaging presentation slides. To open a new file in PowerPoint, click the Start button and then type ‘PowerPoint’. Select PowerPoint . Microsoft PowerPoint Select New and then Blank Presentation .
A new window of Microsoft PowerPoint will appear. There are placeholders in the slide. We can put text, pictures or charts in them. We can choose a theme for the presentation from the Design tab. A theme is a set of design that is applied to the whole presentation. It gives a consistent and an impressive look. Placeholders Chapter 3 43 Data handling
We can choose different layouts from the Layout button in the Home tab. We can also edit, add or delete a placeholder. We can type the text in a placeholder with any desired colors, fonts and sizes. 44 Computing Science Primary 3
We can insert the next slide by clicking the New Slide button in the Slides group. Choose a suitable layout. We can insert pictures into the slide to make it more interesting. First, select the Insert tab and then the Pictures button. Select the picture that you want and click Insert . Chapter 3 45 Data handling
We can drag the picture to a new location. We can also resize it by placing and clicking the cursor at any of its corners and then dragging it to the desired size. Once the slide is done, we can save it. To save the presentation, click the File tab and then the Save As button. Then, select Browse to choose the location to keep the file. 46 Computing Science Primary 3
Type the name of the presentation and click the Save button. To close a presentation, we click the File tab and the Close button. You may also use the Close button at the top right corner of the Window too. A pop-up window will appear asking if you want to save any changes made to it or not. Click Save to save it. Chapter 3 47 Data handling
To open an existing presentation file, open the PowerPoint software. Select Open and then Browse . Select the presentation file that you want and click the Open button. 48 Computing Science Primary 3
To prepare the charts, posters or reports, we can use different kinds of application software. We can use... ...Microsoft Excel ...Microsoft Paint ...Microsoft Word ...Microsoft PowerPoint 56 Computing Science Primary 3
Get into five groups. Each group selects one of these problems. (a) What is the favorite fruit among the students? (b) If you have one million Baht, what would you do? (c) If you were a superhero, what kind of superhero would you be? (d) What would you want to be when you grow up? (e) What are the good characteristics of a good friend? Find the answers from your classmates. You should find ways to collect, organize and analyze your data. Lastly, present your findings in a chart to the class. 3 Get into groups of six. Brainstorm problems or questions that you would like to find out by collecting data from your classmates. Then, decide on a problem or question. Carry out the process of collecting, organizing, analyzing and presenting your findings. 4 1. Microsoft PowerPoint is a presentation graphic software which we can use to present our slide show. 2. When solving some problems, we may need to collect data by either using questionnaires, interviewing or observing first. 3. Then, we need to organize and analyze the data. 4. Lastly, we can present the data using charts, posters or reports. 5. We can use different kinds of application software to prepare the charts, posters and reports. ? Chapter 3 57 Data handling
1. Tick (✓) the uses of Microsoft PowerPoint. To prepare presentation slides To write a report based on the findings of a survey To do simple alterations of photos or pictures To draw and paint pictures To tabulate and calculate data To play slide presentations To convert tables into charts 2. Number the correct steps to get information from a group of people. Gather data by using questionnaires or interviewing. Present information in charts, posters or reports. Organize and analyze collected data. 3. We can present data we collected using charts, posters and reports. When should we use charts, posters and reports for our data? Give your reasons. Charts : Posters : Reports : 58 Computing Science Primary 3
Chapter 4 Information and communication technology We are Indonesian citizens. Who are the digital citizens? Since we are using the Internet more each day for education, entertainment, social interaction and researches, we are fast becoming digital citizens too. People use the Internet to do many things such as to communicate with others, to do businesses and to search for information. These people who use the Internet regularly and effectively are known as the digital citizens. Digital citizenship
60 Computing Science Primary 3 Why do we need to be a good digital citizen? Can we really affect other users with our bad behaviors online? How? Digital citizenship is an idea of how the Internet users should use this technology appropriately and responsibly. Good digital citizens are expected to act according to the generally accepted rules. All good digital citizens should: Have digital etiquette Stand up to cyberbullying Stay safe online Respect copyright Manage their digital footprints Protect their personal information Balance their time
Chapter 4 61 Information and communication technology 1. Analyze the actions below. Which would you do? Tick (✓) the correct columns. 1 Informing parents about a threatening email Doing a research online without checking the reliability Posting a rude remark on a friend’s social media account Opening emails without any suspicion Using a fake name instead of our real names online Replying to requests from strangers online Giving positive and encouraging comments online 2. Which of the above is the worst action? Why do you think so? 3. What are other actions that you always do online? 4. What are other actions that you should not do online? 5. Are you a good digital citizen?
62 Computing Science Primary 3 Protecting our personal information Never give out our personal information online such as our identity card number, address, telephone number, bank account numbers, passwords and plans. We also need to understand that any digital information such as texts, photos or videos that we shared online, can be easily copied and pasted elsewhere. We might not able to get it back. Identity Card Staying safe online Do not believe in whatever information we get online. We need to verify the information with other sources. Never go out with someone we meet online. Inform your parents or teachers if someone online asks for your personal details, says something that makes you upset or asks you to keep secrets. Balancing our time Although there are many benefits of using modern devices, we need to balance our on-screen and off-screen time properly. We need to engage ourselves in ‘real world’ friends and activities such as playing a sport or a musical instrument, singing and picnicking.
Chapter 4 63 Information and communication technology 1. What did you do during your last weekend? List them down. 2 2. We divide these activities into three groups: Active Time: Activities that involve moving around Learning Time: Activities that involve learning or creating new things Screen Time: Activities that involve computer devices and televisions Categorize your activities into the groups. Active Time Learning Time Screen Time 3. Which type of activities did you spend most time on? Why? 4. If you are going to re-organize your time spent, how would you do it? Why? 5. Discuss with your friends if (a) you should increase your Active Time and Learning Time activities. Why? How? (b) you enjoy Active Time and Learning Time activities. Why?