To find out how number-line visualization relates to understanding, the researchers gave children a stack of blank number lines with "0" written on the left end and "20" on the right end.

Even if some of the numbers on a number line have been removed, you can still use it to estimate the value of a number. Let's work out what number is shown by the arrow. Step 1 - Look at the range.

A number line is a useful way of showing the order of numbers and can help you compare and estimate the value of numbers. The arrow on this number line is between 60 and 70. It is less than 65, so ...