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Using a Number Line

Posted by Allan Wilson on the 11th September, 2017

This is our second blog for Maths Week Scotland. Today we are looking at the idea of using a Number Line, a popular manipulative to help young learners with dyscalculia and other numeracy difficulties gain a better understanding of numbers. We are going to focus on the Number Line app from the Math Learning Centre.

Number Line is a simple, but powerful app that helps learners visualise number sequences and develop strategies for understanding addition, subtraction, multiplication and division.

Initially you are presented with a basic number line, with a scale and numbers. You can change the scale, hide numbers and make other changes to the line by selecting appropriate options from the menus at the bottom of the screen and you can also move the light blue slider at the top of the screen to the left or right to show a different subset of numbers on the Line.

Menu options also allow you to set a sum to be calculated and to make annotations on the Number Line. A simple sum, such as 8 + 5 can be represented by starting a 'jump' of 5 places to a starting point of 8 to get an answer of 13.

The Number Line allows for the introduction of the concept of 'negative numbers'. Use the 'Select Numbers' icon to 'Show Negative Numbers'. For example, if you wanted to add (-5) to 3, you would place the left edge of your 'jumper' at 3, then drag the right handle to the left. As soon as you pass your starting point, the jump turns red to indicate a negative number. In this case, 3 + (-5) = -2.

The Number Line app has a useful built-in 'Help' facility - just tap on the 'i' icon in the bottom right corner of the screen for tips on how to use the app. (Only the top half of the guidance is shown in this illustration.)

Low Tech Options

Of course, you don't need an app to make use of a number line (though it does help to make work much neater). It is easy to just draw a line on a sheet of paper (preferably with squares to make it easier to add numbers and jumps. For whole class, or group activities, use a length of string and attach laminated numbers with paper clips. Add a starting point (e.g. '0') at one end of the string and a finishing number, e.g. '10' or '100' at the other end and ask pupils to estimate where other numbers should be placed.

Further Information

A free, downloadable book, 'Learning to Think Mathematically with the Number Line' is available from the Math Learning Centre web site, where you can also find a series of short videos illustrating the use of the Number Line app.