Mathematics - Term 1 - Week 3

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 add 3 and 5, we can start at 3 on a number line and move 5 steps to the right, landing on 8. Conversely, for subtraction, if we have 8 and we subtract 5, we start at 8 and move 5 steps to the left, landing on 3.

Let's add 27 and 45. We can break it down: 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.

Now, let's subtract 56 from 92. Start by subtracting the tens: 90 - 50 = 40. Then, subtract the units: 2 - 6. Since we cannot subtract 6 from 2, we borrow 1 from the tens, making it 12 - 6 = 6. Now combine the results: 40 + 6 = 36. Thus, 92 - 56 = 36.

Let's practice together. Add 34 and 29. Start by adding the tens: 30 + 20 = 50. Then, add the units: 4 + 9 = 13. Combine these results: 50 + 13 = 63. Now, try adding 48 and 37 with a partner, showing your work step by step.

Now, let's work on subtraction. Subtract 73 from 120. Start with the tens: 120 - 70 = 50. Then, subtract the units: 0 - 3. Since we can't do that, we borrow from the tens, making it 10 - 3 = 7. Combine the results: 50 + 7 = 47. Try subtracting 85 from 150 with your partner, showing your calculations.

Now it's your turn! Solve the following problems on your own: 1) 65 + 28 = ? 2) 94 - 37 = ? 3) 53 + 46 = ? 4) 100 - 45 = ? Remember to show all your working clearly. After you finish, we will review the answers together.

• 32
• 42
• 52
• 22

Answer: 42

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

• 45
• 50
• 55
• 60

Answer: 45

When you subtract 45 from 90, you get 45.

Answer: 53

34 plus 19 equals 53.

Answer: 49

78 minus 29 equals 49.

• 80
• 90
• 100
• 70

Answer: 90

56 plus 34 equals 90.

• 45
• 55
• 65
• 35

Answer: 45

120 minus 75 equals 45.

Answer: 40

22 plus 18 equals 40.

Answer: 33

100 minus 67 equals 33.