First Grade: Addition and Subtraction

Build mental math skills.

Mental math refers to the math we do “in our head,” without writing anything down. Help your child strengthen their mental math skills by creating opportunities for them to think flexibly about numbers throughout the day. Spice up your commute to school by practicing skip counting by 2s, 5s, and 10s, practice counting back from 20 when microwaving leftovers, or play a quick game of “Ten Fingers.” To play, say a number between 1 and 10, and ask your child to show you that many fingers. Then ask how many more fingers they’ll need to make ten fingers. This reinforces making combinations of 10, which will help them with more complex addition and subtraction in the future. 

Play “What’s My Number” to improve their mental math skills.

Think of a number (start with a number 20 or less and increase when your child is ready for more of a challenge) and give hints describing that number. Use hints like:

• I‘m thinking of a number that is less than 20 (or 100).
• I’m thinking of a number that is greater than 2 (or 20).
• My number is odd (or even)
• If you add 2 (or 5 or 10, etc) to my number, it is ___.
• If you subtract 1 (or 2 or 10, etc) from my number, it is ____.
• If you double my number, it is ____.

Here’s an example for the number 8:

• I’m thinking of an even number.
• My number is less than 10.
• If you double me, you get 16.
• What is my number?