-0/-1
12 - 0 = ?
12
Write the fact family for the numbers:
3, 1, 4
3 + 1 = 4
1 + 3 = 4
4 - 1 = 3
4 - 3 = 1
Explain how you would count up to find the difference:
5 - 2 = ?
Start at 2 and count up to 5. The difference is 3.
Explain how you would count back to find the difference:
5 - 3 = ?
Start at 5 and count back to 3. The difference is 2.
We use these to easily solve addition and subtraction problems.
strategies
12 - 1 = ?
11
Write the fact family for the numbers:
7, 10, 3
3 + 7 = 10
7 + 3 = 10
10 - 3 = 7
10 - 7 = 3
Explain how you would count up to find the difference:
8 - 1 = ?
Start at 1 and count up to 8. The difference is 7
Explain how you would count back to find the difference:
10 - 7 = ?
Start at 10 and count back to 7. The difference is 3.
The answer for an addition equation.
sum
45 - 0 = ?
45
Write the fact family for the numbers:
6, 12
6 + 6 = 12
12 - 6 = 6
Explain how you would count up to find the difference:
14 - 4 = ?
Start at 4 and count up to 14. The difference is 10.
Explain how you would count back to find the difference:
18 - 9 = ?
Start at 18 and count back to 9. The difference is 9.
When you count by a number other than one.
skip counting
120 - 1 = ?
119
Write the fact family for the numbers:
20, 7, 13
7 + 13 = 20
13 + 7 = 20
20 - 13 = 7
20 - 7 = 13
Explain how you would count up to find the difference:
30 - 26 = ?
Start at 26 and count up to 30. The difference is 4.
Explain how you would count back to find the difference:
25 - 15 = ?
Start at 25 and count back to 15. The difference is 10.
Fill in the blanks:
When a number can be divided equally it is a ____ number.
When a number cannot be divided equally it is an ____ number.
even
odd
1,480 - 1 =
1,479
Write the fact family for the numbers:
15, 25, 10
10 + 15 = 25
15 + 10 = 25
25 - 10 = 15
25 - 15 = 10
Explain how you would count up to find the difference:
67 - 47 = ?
Start at 47 and count up to 67. The difference is 20.
Explain how you would count back to find the difference:
89 - 59 = ?
Start at 89 and count back to 59. The difference is 30.
The answer to a subtraction equation.
difference