Introduction to Addition

A. 2 ✓

When you combine one item with another item, you have two items total. This is the fundamental concept of addition.

Why the others are wrong:
- B (1): This ignores one of the numbers entirely.
- C (3): This adds an extra unit that wasn't in the problem.
- D (4): This is too large and doesn't match the operation.

A. 5 is correct — You start with 2 apples and add 3 more, so 2 + 3 = 5 apples total.

B. 6 is wrong — This might come from accidentally adding an extra apple or misreading the numbers.

C. 3 is wrong — This is just the number you bought, ignoring the apples you already had.

D. 2 is wrong — This is only your starting amount; it doesn't include the apples you bought.

A. 9 ✓

When you add 4 and 5 together, you get 9. You can count it out: starting at 4, count up 5 more (5, 6, 7, 8, 9).

Why the others are wrong:
- B. 10 – This would be 5 + 5, not 4 + 5
- C. 7 – This is only 3 more than 4, not 5 more
- D. 8 – This is only 4 more than 4, not 5 more

A. 20 ✓

When you add 10 + 10, you combine two groups of 10, which equals 20.

Why the others are wrong:
- B (30): This would be 10 + 20, not 10 + 10
- C (10): This is just one of the numbers, not the sum
- D (40): This would be 10 + 30, or 20 + 20, not 10 + 10

A. 9 ✓

When you add 7 and 2 together, you get 9. You can count it out: 7, 8, 9—that's two more steps.

Why the others are wrong:
- B (10): That would be 7 + 3, not 7 + 2
- C (11): That would be 7 + 4
- D (12): That would be 7 + 5

A. 5 is correct — You start with 4 pages and add 1 more, so 4 + 1 = 5.

B. 8 is wrong — This might come from doubling 4, but we're only adding 1, not doubling.

C. 7 is wrong — This doesn't match any operation on 4 and 1.

D. 12 is wrong — This is too large; multiplying 4 × 3 doesn't match the problem.

A. 6 ✓

When you add 3 + 3, you combine two groups of three to get six. You can count it on your fingers: three fingers on one hand plus three on the other equals six total.

Why the others are wrong:
- B (5): This skips one—you'd only get 5 if you added 3 + 2
- C (4): This is too low; you'd need 3 + 1 to get 4
- D (3): This is just one of the numbers, not the sum

A. 5 is correct — You add the cats together: 3 + 2 = 5.

B. 6 — Wrong; this might come from miscounting or adding incorrectly.

C. 12 — Wrong; this looks like multiplying (3 × 4 or 2 × 6), which we don't need here.

D. 13 — Wrong; there's no math operation that gives this answer from 3 and 2.

Correct answer: A (10)

When you add 2 + 8, you combine two groups: two items plus eight items equals ten items total.

Why the others are wrong:
- B (20): This would be 2 × 10 (multiplication, not addition)
- C (15): This is too high; there's no mathematical operation that gives this result
- D (14): This is also too high; it doesn't match 2 + 8

A. 10 ✓

When you add 6 and 4 together, you get 10. You can count it out: 6, 7, 8, 9, 10—that's four more steps from 6.

Why the others are wrong:
- B (5): This is smaller than either number you're adding, so it can't be right.
- C (7): This is only 1 more than 6, not enough when adding 4.
- D (8): This is close but falls 2 short of the correct sum.