Mathematics - Term 1 - Week 3

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 blocks. 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 to the right, landing on 8. Conversely, if we have 8 apples and take away 3, we move 3 steps to the left on the number line, landing on 5.

Let's solve the problem: 27 + 45. First, we can break down the numbers into tens and units: 27 is 20 + 7, and 45 is 40 + 5. Adding the tens together gives us 20 + 40 = 60, and adding the units gives us 7 + 5 = 12. Now, we combine these results: 60 + 12 = 72. Therefore, 27 + 45 = 72.

Now, let's look at the subtraction problem: 63 - 28. We can break it down similarly: 63 is 60 + 3, and 28 is 20 + 8. First, we subtract the tens: 60 - 20 = 40. Next, we subtract the units: 3 - 8. Since we cannot subtract 8 from 3, we need to borrow 1 from the tens, making it 13. So, 13 - 8 = 5. Now, we combine the results: 40 + 5 = 45. Thus, 63 - 28 = 45.

Let's try some guided practice together. Solve the following problems: 1) 34 + 29, and 2) 85 - 47. For the first problem, break down the numbers: 34 is 30 + 4 and 29 is 20 + 9. Adding the tens gives us 30 + 20 = 50, and adding the units gives us 4 + 9 = 13. Combine these to get 50 + 13 = 63. For the second problem, break it down: 85 is 80 + 5 and 47 is 40 + 7. Subtract the tens: 80 - 40 = 40, and then the units: 5 - 7 requires borrowing, so we get 15 - 7 = 8. Combine to get 40 + 8 = 48.

Now it's your turn to practice independently. Solve the following problems on your own: 1) 56 + 34, 2) 92 - 19, 3) 47 + 28, and 4) 73 - 36. Remember to show your working clearly. After you finish, we will review the answers together and discuss any mistakes.

• 42
• 32
• 22
• 40

Answer: 42

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

• 35
• 45
• 55
• 25

Answer: 35

64 - 29 equals 35 after performing the subtraction.

Answer: 101

82 + 19 equals 101 when you add the two numbers.

Answer: 27

50 - 23 equals 27 after performing the subtraction.

• 57
• 47
• 67
• 37

Answer: 57

39 + 18 equals 57 when you add the two numbers.

• 55
• 65
• 75
• 85

Answer: 55

100 - 45 equals 55 after performing the subtraction.

Answer: 110

76 + 34 equals 110 when you add the two numbers.

Answer: 53

90 - 37 equals 53 after performing the subtraction.