Add 2-digit numbers ... methods for subtracting a one-digit number from a three-digit number. How to add and subtract in your head Explore how to use mental methods for addition and subtraction.

Add 2-digit numbers ... methods for subtracting a one-digit number from a three-digit number. How to add and subtract in your head Explore how to use mental methods for addition and subtraction.

Use models or drawings and explain your written method. Understand that in subtracting one three-digit number from another three-digit number, you are subtracting hundreds from hundreds ...

Previously in Massachusetts, students were introduced to the algorithm for multi-digit addition and subtraction in 2nd grade. In California, students learned the algorithms for addition ...