Here is a row of squares built from matchsticks. One square takes 4 sticks. Two squares side by side take 7 sticks, because the middle stick is shared. Three squares take 10.

Here are two growing patterns marked out along the number line. Each mark shows a count, and the gap between one mark and the next is the jump.

Here is a second pattern. Look at how big each gap is.

One of these grows by the same jump every time. The other grows by a jump that gets bigger. See if you can tell which is which from the gaps.

Now we work two patterns on the same number line, one after the other. One pupil comes up to mark a count while the rest of the class watches and agrees or corrects out loud. Press Reset to clear the line before the second pattern.

Then press Reset and try a shrinking pattern: 20, 16, 12. Set the start to 20, find the jump, and jump back to land on each count. What comes next?