Number Line
Instructions
1. Select how many divisions you require by moving the slider to the appropriate position.
2. Type a starting and ending value into the two provided input boxes (0 and 10 are default). These values can be positive or negative, integers or decimals.
3. In between values can be revealed by click on its question mark or clicking on the reveal all button.
4. Drag the purple triangle into a desired position, followed by the blue triangle. In order to replicate an addition, the purple triangle should be on right of the blue one, on its left for a subtraction.
5. Click on the 'Steps/Jump' button to change between showing steps between to two markers (moving one division at a time) and a jump (one single motion). The question marks on the steps and jump can also be clicked on to reveal what value is being added/subtracted.
Ideas for use
1. Mental addition and subtraction: Selecting two positions for the markers, students need to work out how to get from one to the other (jump). Using the steps option can act as support. The difficulty is made variable by your choice of start and end input values. Consider using positive/negative integer/decimals inputs but also consider whether each step will be small/large or an integer/decimal value.
2. Mental multiplication: Leaving the first input as zero, the second input could be selected so that a times table exists along the number line. Clicking on the individual question marks will reveal answers. The steps option can e there to support the understanding.
3. Calculations with negatives: Pupils can obtain a better understanding of negatives by using negative numbers on the number line and the steps between being negative (by having a small number on the second input value than the first). To this end, it can be shown that adding a negative and subtracting a positive give the same result, and that subtracting a negative is the same as adding a positive.
4. Arithmetic Sequences: A sequence can be created along the number line for which first term, common difference and term-to-terms can be highlighted.