In this lesson, students put all of their addition and subtraction skills together to solve equations. Julia begins with a Number of the Day warm up activity, followed by practicing 2 and 3 ...

It looks different, but it still has two parts ... Just like with addition, we can use a part-whole model to help partition larger numbers to make them easier to deal with in subtraction problems.

Add 2-digit numbers ... 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.