Hi, I'm Dario!

I will help you learn how to work out differences between numbers in your head.

The Difference Bar is a tool that helps you find differences by breaking numbers up.

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The Difference Bar

Mouse instructions

Move around the screen and select a Button.

Select and move some items like the sliders (slider).

Keyboard instructions

Use the Tab key to move to the different elements of the screen.

Use the Shift + Tab  key to move backwards through the screen.

Press the Enter or Return key to use the button that you have selected.

Use the arrow keys arrow to move the sliders.

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You can use 'round to the nearest 10' to work out the difference between 39 and 67. First, add 1 to 39 to get 40. Then, add 27 to get 67. So, the total difference is 1 + 27, which is 28.


You can use 'round to the nearest 10' strategy to help work out your answer. Or you can look another strategy in the Next hint.

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