Addition And Subtraction Properties - 1st Grade Math

1. What is the sum using the commutative property: if $8 + 3 = 11$, what is $3 + 8$?

   $11$. Swapping addends gives the same sum.

2. What is $7 + 0$ using the identity property of addition?

   $7$. Adding zero leaves the number unchanged.

3. What is 7 − 0?

   7. When you take away 0, the number stays the same.

4. What is $3 + 7 + 5$ by grouping $3 + 7$ first?

   $15$. First add $3+7=10$, then $10+5=15$.

5. What is $2 + 7 + 3$ using $(7 + 3)$ to make $10$?

   $12$. Regroup as $2 + (7 + 3) = 2 + 10 = 12$.

6. Find the value: $2 + (5 + 3)$ (use the associative property to regroup).

   $10$. Calculate inside parentheses first: $5+3=8$, then $2+8=10$.

7. What is $0 + 12$ using the identity property of addition?

   $12$. Zero plus any number equals that number.

8. What is $2 + 6 + 4$ by making a ten (use grouping)?

   $12$. Group $6+4=10$, then $2+10=12$.

9. What is the sum if you switch the addends in $8 + 3$ to $3 + 8$?

   $11$. Commutative property: order doesn't change the sum.

10. What property of addition says $(a + b) + c = a + (b + c)$?

    Associative property of addition. Grouping doesn't change the sum.

11. Does 4 + 2 make the same amount as 2 + 4?

    Yes. Both make 6. You can switch the order when you add, and the total stays the same.

12. What property says $a + 0 = a$ (adding zero does not change the number)?

    Identity property of addition (zero property). Adding zero leaves any number unchanged.

13. Which property justifies changing $(2 + 6) + 4$ to $2 + (6 + 4)$?

    Associative property of addition. Regrouping to make 10 simplifies addition.

14. What is $10 - 6$ if you know $6 + 4 = 10$?

    $4$. Since $6 + 4 = 10$, then $10 - 6 = 4$.

15. What is $5 + 5 + 2$ by grouping $5 + 5$ first?

    $12$. First add $5+5=10$, then $10+2=12$.

16. What is $5 + 7 + 3$ if you group $7 + 3$ first?

    $15$. Group $7 + 3 = 10$, then $5 + 10 = 15$.

17. Identify the property used: $7 + 9 = 9 + 7$.

    Commutative property of addition. Numbers can be added in any order.

18. What property of addition says $(a + b) + c = a + (b + c)$ (you can regroup addends)?

    Associative property of addition. Grouping doesn't matter when adding multiple numbers.

19. What is $1 + 6 + 4$ using $(6 + 4)$ to make $10$?

    $11$. Regroup as $1 + (6 + 4) = 1 + 10 = 11$.

20. Identify the property used: $(2 + 4) + 3 = 2 + (4 + 3)$.

    Associative property of addition. Parentheses can be moved without changing the sum.

21. What is $9 + 1 + 4$ by grouping to make $10$ first?

    $14$. Group $9+1=10$, then $10+4=14$.

22. What is $4 + 6 + 7$ using $(4 + 6)$ to make $10$?

    $17$. Regroup as $(4 + 6) + 7 = 10 + 7 = 17$.

23. Which property justifies changing $2 + 9$ to $9 + 2$ to add more easily?

    Commutative property of addition. Switching addends makes mental math easier.

24. What is $8 + 2 + 6$ by grouping $8 + 2$ first?

    $16$. First add $8+2=10$, then $10+6=16$.

25. What is $2 + 6 + 4$ if you use grouping to make $10$?

    $12$. Group $6 + 4 = 10$, then $2 + 10 = 12$.

26. What property of addition says $a + b = b + a$?

    Commutative property of addition. Order doesn't matter when adding numbers.

27. What is $15 - 0$ using the zero property of subtraction?

    $15$. Subtracting zero leaves the number unchanged.

28. What property of addition says $a + 0 = a$?

    Additive identity property (zero property of addition). Adding zero doesn't change a number.

29. What is $12 - 9$ if you know $9 + 3 = 12$?

    $3$. Since $9 + 3 = 12$, then $12 - 9 = 3$.

30. What is $3 + 8 + 2$ if you group $8 + 2$ to make $10$?

    $13$. Group $8 + 2 = 10$, then $3 + 10 = 13$.

31. What is $6 + 9$ if you use the commutative property to think $9 + 6$?

    $15$. Switching addends gives the same sum.

32. What is $11 - 3$ if you know $8 + 3 = 11$?

    $8$. Since $8 + 3 = 11$, then $11 - 3 = 8$.

33. What is $4 + 9$ using the commutative property (swap the addends)?

    $13$. Same as $9+4$ by swapping order.

34. What is $3 + 9 + 7$ using $(3 + 7)$ to make $10$?

    $19$. Regroup as $(3 + 7) + 9 = 10 + 9 = 19$.

35. Which property justifies $7 + 0 = 7$?

    Identity property of addition (zero property). Adding zero doesn't change the value.

36. What is $9 + 1 + 6$ if you group $9 + 1$ first?

    $16$. First $9 + 1 = 10$, then $10 + 6 = 16$.

37. What is $8 + 2 + 6$ using $(8 + 2)$ to make $10$?

    $16$. Regroup as $(8 + 2) + 6 = 10 + 6 = 16$.

38. What is $7 + 6$ using the commutative property (swap the addends)?

    $13$. Same as $6+7$ by swapping order.

39. What is $7 + 3 + 5$ if you group $7 + 3$ first?

    $15$. First $7 + 3 = 10$, then $10 + 5 = 15$.

40. What is $3 + 8$ if you know $8 + 3 = 11$?

    $11$. Commutative property: order doesn't change the sum.

41. What is $5 + 9 + 1$ using $(9 + 1)$ to make $10$?

    $15$. Regroup as $5 + (9 + 1) = 5 + 10 = 15$.

42. What is $9 + 5 + 1$ using $(9 + 1)$ to make $10$?

    $15$. Regroup as $(9 + 1) + 5 = 10 + 5 = 15$.

43. What is $6 + 3 + 4$ by grouping $6 + 4$ first?

    $13$. Group $6+4=10$, then $10+3=13$.

44. What is $7 + 8 + 3$ using $(7 + 3)$ to make $10$?

    $18$. Regroup as $(7 + 3) + 8 = 10 + 8 = 18$.

45. Find the value: $(2 + 5) + 3$ (use the associative property to regroup).

    $10$. Calculate inside parentheses first: $7+3=10$.

46. Identify the property used: $5 + 0 = 5$.

    Additive identity property (zero property of addition). Adding zero doesn't change the value.

47. What is $4 + 8 + 2$ if you group $8 + 2$ to make $10$?

    $14$. Group $8 + 2 = 10$, then $4 + 10 = 14$.

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