Mathematics - Term 2 - Week 1

Addition is the process of finding the total or sum by combining two or more numbers. Subtraction, on the other hand, involves taking one number away from another to find the difference. For example, if you have 5 apples and you buy 3 more, you can add them together to find you have 8 apples. Conversely, if you have 10 apples and give away 4, you subtract to find you have 6 apples left. Visual models like number lines or counters can help illustrate these concepts.

Let's solve the problem: 23 + 15. Start by adding the units: 3 + 5 = 8. Next, add the tens: 2 + 1 = 3. Therefore, 23 + 15 = 38. We can visualize this using a number line, jumping from 23 to 38 in two steps: first to 30 (adding 7), then to 38 (adding 8).

Now, let's look at subtraction with the problem: 45 - 17. Start with the units: 5 - 7. Since we can't subtract 7 from 5, we need to borrow 1 from the tens, making it 15 - 7 = 8. Now, for the tens: 3 - 1 = 2. So, 45 - 17 = 28. A visual model can help show how borrowing works.

Let's work on this together: 34 + 29. First, add the units: 4 + 9 = 13. Write down 3 and carry over 1. Now add the tens: 3 + 2 + 1 (the carry) = 6. So, 34 + 29 = 63. Can anyone explain how we handled the carry?

Now, let's try this subtraction problem: 62 - 25. Start with the units: 2 - 5. We need to borrow, so we change 6 to 5 and make the 2 into 12. Now, 12 - 5 = 7. For the tens: 5 - 2 = 3. Therefore, 62 - 25 = 37. Who can show me how they visualized this problem?

Now it's your turn! Solve the following problems on your own and show your working clearly: 1) 57 + 36, 2) 84 - 19, 3) 45 + 28, 4) 73 - 46. Remember to check your work and reflect on any mistakes you might make. Use visual models if it helps!

• 27
• 25
• 30
• 22

Answer: 27

Adding 12 and 15 gives a total of 27.

• 27
• 30
• 25
• 22

Answer: 27

Subtracting 23 from 50 results in 27.

Answer: 82

Adding 34 and 48 gives a total of 82.

Answer: 45

Subtracting 45 from 90 results in 45.

• 65 - 20 = 45
• 50 - 30 = 20
• 80 - 15 = 65
• 70 - 25 = 45

Answer: 70 - 25 = 45

The correct subtraction is 70 - 25, which equals 45.

• 63
• 62
• 64
• 61

Answer: 63

The sum of 29 and 34 is 63.

Answer: 63

Subtracting 37 from 100 leaves you with 63.

Answer: 95

Adding 76 and 19 gives a total of 95.