# Addition & Subtraction facts with a number line

The addition and subtraction facts interactive activity has been greatly improved. A tutorial video has finally been added and the interface has been redesigned with many new features. The automatic mode has been removed,in its place is a new a new random action button. When clicked a random number fact problem is created, the clouds of fog or sea transparency hide the penguins. This allow the teacher to reveal various parts and so the pupils can deduce what the sum or subtraction is.

## A number line to represent number facts

Number lines are great for representing addition and subtraction. So you can now view an automatic number line to represent any of the addition or subtraction facts up to twenty.

## Editing - addition or subtraction facts up to twenty

As well as creating random problems, the editing controls have been change so that they work with the number line. Now sliders are used to set the total number of penguins and the how many are on the first iceberg. The knob for the slider should coincide with the ends of the arcs on the number line.