Mathematics - Term 4 - Week 7

Addition is the process of combining two or more numbers to find their total, while subtraction involves taking one number away from another. To visualize these operations, we can use number lines, counters, or drawings. For example, if we have 5 apples and add 3 more, we can represent this on a number line by starting at 5 and moving 3 steps forward to reach 8. Conversely, if we have 8 apples and take away 3, we start at 8 and move 3 steps back to land on 5.

Let's solve the problem 27 + 45. We can break this down: First, add the tens: 20 + 40 = 60. Next, add the units: 7 + 5 = 12. Now, combine these results: 60 + 12 = 72. Therefore, 27 + 45 = 72.

Consider the problem 65 - 28. Start by subtracting the tens: 60 - 20 = 40. Then, subtract the units: 5 - 8. Since we can't subtract 8 from 5, we borrow 1 from the tens, making it 15 - 8 = 7. Now, combine the results: 40 + 7 = 37. Thus, 65 - 28 = 37.

Now, let's practice together. Solve the following problems: 1) 34 + 29. Break it down into tens and units. 2) 82 - 47. Remember to borrow if necessary. Work with a partner and discuss your strategies. After solving, we will review the answers as a class.

Complete the following problems on your own: 1) 56 + 37 2) 91 - 54 3) 48 + 26 4) 73 - 29. Show all your working clearly. Once finished, check your answers with a partner and discuss any mistakes.

• 42
• 32
• 52
• 40

Answer: 42

Adding 15 and 27 gives a total of 42.

• 55
• 65
• 75
• 85

Answer: 55

Subtracting 45 from 100 results in 55.

Answer: 112

Adding 78 and 34 gives a total of 112.

Answer: 34

Subtracting 29 from 63 results in 34.

• 81
• 71
• 91
• 61

Answer: 81

The sum of 45 and 36 is 81.

• 53
• 63
• 73
• 83

Answer: 53

Subtracting 37 from 90 gives 53.

Answer: 41

Adding 22 and 19 results in 41.

Answer: 32

Subtracting 18 from 50 gives 32.