Early MathCount by 1, 2, 5, 10 up to 20
Write the missing number in each row.
One sheet, four different steps. Each row counts by its own amount and shows both neighbors of the blank, so the step is something a child works out from the row rather than something the page tells them. Free printable sheets, with an answer key.
If they get stuck

The answer key prints on a separate page.
Every question is a complete mathematical pattern, not a row of unrelated random numbers. The sequences step by one, two, five, and ten, and only introduces a larger step when the selected number range can show the pattern clearly. Fives and tens begin on their familiar multiples. The blank always sits inside the sequence rather than at an end, so a child can count forward from the left and check the answer against the number on the right.
MIXING THE STEPS IS THE EXERCISE HERE, and it is a different one from practicing a single step. A row on this sheet does not say what it counts by, so the first thing to do with it is read two numbers and work that out — which is why every row prints both sides of the gap. A sheet that counts by fives all the way down asks nothing of that kind, and is the better sheet for learning fives; both are below.
One question from a sheet like this one, worked a step at a time — with a sentence saying what just happened and why.
Mixed skip counting sequences, step by step