What is a number line? A number line is a straight line with numbers written in order from lowest to highest. Number lines can go up to any number, such as 10, 20, or even more! They help you to see ...

When you estimate a number you decide approximately, or roughly, how big that number is. To estimate accurately, you need to have a good understanding of the value and order of numbers. A number line ...

Addition & subtraction strategies to solve two-digit equations using an open number line. In this lesson, students go over using different addition and subtraction strategies to solve two-digit ...