First Grade Math Strategies

+1 Facts
Count up one to find the answer (the sum).
For example, if the problem is 5 + 1, then count up once from five (5, 6). Using a number line
or a ruler to count up one provides hands on and visual support of this concept.

-1 Facts
Count back one to find the answer (the difference).
For example, if the problem is 5 - 1, then count back one from five (5, 4) Using a number line
or a ruler to count back one provides hands on and visual support of this concept.

+0 Facts
Zero has no effect. The answer (the sum) will be the addend that is not zero.
For example, if the problem is 7 + 0, the answer is 7.

-0 Facts
Zero has no effect. The answer (the difference) will be the addend that is not zero.
For example, if the problem is 7 - 0, the answer is 7.

Adding Doubles
Use the doubles rap:
0 plus 0 equals 0, Oh!
1 plus 1 equals 2, Eew!
2 plus 2 equals 4, More!
3 plus 3 equals 6, Kicks!
4 plus 4 equals 8, That's Great!
5 plus 5 equals 10, Again!
6 plus 6 equals 12, Dig and Delve!
7 plus 7 equals 14, Let's Lean!
8 plus 8 equals 16, You're Keen!
9 plus 9 equals 18, Jelly Bean!
10 plus 10 equals 20, That's Plenty!

We use matching towers of linking cubes to support this concept development in class. Two rows
or columns of pennies or blocks at home will provide hands-on support while practicing at home.

Subtracting a Number From Itself
The answer (the difference) is always zero when a number is subtracted from itself.
For example, 7 - 7 = 0.