Nuacht

You can find the difference between two numbers in more than one way. You can count up from the smaller number to the larger number. Or, you can count back from the larger number to the smaller number ...
BBC

Subtraction within 10

Subtraction is taking away one number from another. When you subtract it gives you the difference between two numbers. Here are 7 blocks. If you take away three blocks, how many are left? There would ...