Mathematics - Term 2 - Week 1

Addition is the process of combining two or more numbers to find a 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 we 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 we subtract 3, we move 3 steps to the left on the number line, landing on 5.

Let's solve the problem 23 + 17. We can break this down: First, add the tens: 20 + 10 = 30. Then, add the units: 3 + 7 = 10. Now, combine these results: 30 + 10 = 40. Therefore, 23 + 17 = 40.

Consider the problem 45 - 19. Start by subtracting the tens: 40 - 10 = 30. Next, subtract the units: 5 - 9. Since we can't subtract 9 from 5, we borrow 1 from the tens, making it 15 - 9 = 6. Now, combine the results: 30 + 6 = 26. Thus, 45 - 19 = 26.

Now, let's work on some problems together. First, calculate 34 + 29. Break it down: 30 + 20 = 50 and 4 + 9 = 13. Combine these: 50 + 13 = 63. Next, try 72 - 34. Start with the tens: 70 - 30 = 40, then the units: 2 - 4 (borrow 1) gives us 12 - 4 = 8. Combine: 40 + 8 = 38. Discuss your strategies with a partner.

Now it's your turn! Solve the following problems on your own: 1) 56 + 37, 2) 81 - 45, 3) 29 + 68, 4) 90 - 23. Show all your working steps clearly. After you finish, exchange your work with a partner to check for accuracy and discuss any mistakes.

• 42
• 32
• 52
• 22

Answer: 42

15 + 27 equals 42 when you add the tens and units.

• 35
• 45
• 55
• 25

Answer: 35

64 - 29 equals 35 after borrowing from the tens.

Answer: 84

Adding 48 and 36 gives you 84.

Answer: 55

Subtracting 18 from 73 results in 55.

• 50 - 20 - 3
• 50 - 30 + 7
• 50 - 20 + 3
• 50 - 10 - 13

Answer: 50 - 20 + 3

This expression correctly breaks down the subtraction.

• 55
• 65
• 75
• 85

Answer: 55

100 - 45 equals 55.

Answer: 72

Adding 25 and 47 gives you 72.

Answer: 53

Subtracting 37 from 90 results in 53.