Place Value Number Line

A number line is a common representation of integers used to teach concepts of positive and negative numbers, zero, place-value, and arithmetic operations. The *Place Value Number Line* manipulative is designed to introduce, practice, and test skills in representing place value on a number line.

You may select from six levels of difficulty (Tens, Hundreds, Thousands, Millions, Billions, Decimals) and from 1 to 3 dots. There are three modes (Explore, Practice, Test). Choose the desired difficulty, number of dots, and mode from the drop-down menus. Click on the plus Zoom button to add a number line and increase the precision by a factor of 10. Clicking on the minus Zoom button will remove one number line and one level of precision.

In *Explore* mode, you can place dots on a number line by dragging them from the dot bar to the number line. The value of the location on the number line is displayed above the dot. The blue shaded area that appears on the number line after the dot is placed represents the range of the next number line.

In the *Practice* mode with one dot, you are asked to drag the dot onto the number line to match the value shown. A prompt will appear that will guide you to complete the next step. Click on the *Next Problem* button for a new problem.

In the *Practice* mode with two dots, you areasked to drag one of the two dots onto the number line to match the value shown. You are then asked to drag the other dot so that its value is a given amount more or less.

In the *Practice* mode with three dots, you areasked to drag the first and third dots onto the number line to match given values. You must then drag the second dot so that it is exactly halfway between the other two.

The *Test* mode has the same functions as in the *Practice* mode, with no prompts. To check whether you have solved the problem, click on the *Check* button!