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 finding the difference between numbers by taking one number away from another. To visualize these operations, we can use number lines, counters, or drawings. For example, if we add 3 + 5, we can start at 3 on a number line and move 5 steps to the right to land on 8. Conversely, for subtraction, if we have 8 - 3, we start at 8 and move 3 steps to the left to arrive at 5.

Let's solve the problem 27 + 45. We can break it down into parts: first, add the tens (20 + 40 = 60), then add the units (7 + 5 = 12). Now, combine these results: 60 + 12 = 72. Therefore, 27 + 45 = 72.

Consider the subtraction problem 56 - 29. We can regroup if necessary: 56 can be thought of as 50 + 6. Subtracting 20 from 50 gives us 30, and subtracting 9 from 6 requires borrowing, giving us 30 - 9 = 27. Thus, 56 - 29 = 27.

Now, let’s try some problems as a class. First, solve 34 + 19. Break it down: add the tens (30 + 10 = 40) and the units (4 + 9 = 13). Combine these to find the answer. Next, for 72 - 38, we can regroup: 72 is 70 + 2. Subtract 30 from 70 to get 40, and then subtract 8 from 2, which requires borrowing. Work through these problems together, discussing each step.

Now it's your turn! Solve the following problems on your own: 45 + 36, 81 - 54, 29 + 47, and 63 - 28. Remember to show your working clearly. After you finish, review your answers and check for any mistakes. If you find errors, think about what strategy you could use to correct them.

• 42
• 32
• 22
• 52

Answer: 42

15 + 27 equals 42 when you add the two numbers together.

• 63
• 73
• 57
• 47

Answer: 63

100 minus 37 equals 63.

Answer: 82

Adding 58 and 24 gives a total of 82.

Answer: 45

Subtracting 45 from 90 results in 45.

• 63
• 53
• 73
• 43

Answer: 63

34 + 29 equals 63.

• 47
• 57
• 67
• 37

Answer: 47

76 minus 29 equals 47.

Answer: 83

The sum of 45 and 38 is 83.

Answer: 53

Subtracting 19 from 72 gives 53.