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. For example, if you have 5 apples and you add 3 more, you have a total of 8 apples. Conversely, if you have 8 apples and you give away 3, you are left with 5 apples. Visual models, such as number lines and counters, can help illustrate these concepts clearly.

Let's consider the addition problem 27 + 45. To solve this, we can break it down: First, add the tens (20 + 40 = 60) and then the units (7 + 5 = 12). Now, combine these results: 60 + 12 = 72. Therefore, 27 + 45 = 72.

For the subtraction problem 63 - 29, we can also break it down. Start by subtracting the tens (60 - 20 = 40) and then the units (3 - 9). Since we cannot subtract 9 from 3, we borrow 1 from the tens, making it 13 - 9 = 4. Now, combine the results: 40 + 4 = 34. Thus, 63 - 29 = 34.

Now, let's practice together. Solve the addition problem 34 + 56. Start by adding the tens: 30 + 50 = 80, and then the units: 4 + 6 = 10. Combine these results to find the total. Discuss your thought process with a partner and share your answer.

Next, let's work on the subtraction problem 85 - 47. Begin by subtracting the tens: 80 - 40 = 40, and then the units: 5 - 7. Since we cannot subtract 7 from 5, we need to borrow. Discuss how you would handle this with your group and find the final answer.

Now it's your turn! Solve the following problems on your own: 1) 72 + 19 2) 54 - 26 3) 88 + 34 4) 91 - 45. Show all your working steps clearly. After you finish, exchange your work with a partner to check for accuracy and discuss any mistakes.

• 72
• 82
• 92
• 52

Answer: 82

Adding 45 and 37 gives you 82.

• 42
• 52
• 62
• 72

Answer: 42

Subtracting 58 from 100 results in 42.

Answer: 92

Adding 63 and 29 gives you 92.

Answer: 41

Subtracting 34 from 75 results in 41.

• 43
• 53
• 33
• 23

Answer: 43

Adding 29 and 14 gives you 43.

• 43
• 53
• 63
• 73

Answer: 43

Subtracting 47 from 90 results in 43.

Answer: 75

Adding 48 and 27 gives you 75.

Answer: 53

Subtracting 29 from 82 results in 53.