A shrinking sequence hides a rule just as a growing one does — it takes a fixed amount away each time. These free printable worksheets show a sequence that counts down with one number missing, and ask a child to find the step and fill the gap.
If they get stuck
The answer key prints on a separate page.
Every sequence subtracts the same amount from one term to the next: 30, 25, 20, 15 steps down by five each time. The child compares neighboring terms to find the step, then applies it to the blank. Naming the constant difference is the reasoning that later becomes a linear rule, met here while the numbers are small enough to check by counting.
The blank sits inside the sequence, not at the end, so a child cannot simply keep counting down; they have to work in both directions to be sure the missing term fits its neighbors on each side. Numbers stay friendly and the subtraction stays within reach, so the work is spotting the step rather than the arithmetic.
One question from a sheet like this one, worked a step at a time — with a sentence saying what just happened and why.
Decreasing number patterns, step by step