Early MathPicture patterns, units of up to 3
Circle the picture that comes next.
Finding the part that repeats is the beginning of algebra, and it can be done with pictures years before it can be done with numbers. These free printable worksheets show a row of repeating pictures with one gap, and three pictures to choose from.

The answer key prints on a separate page.
The levels step through the units a curriculum teaches in order: two pictures (AB) first, then three (AAB, ABB, ABC). Each level mixes every pattern of that length, so a page is a level rather than one kind of pattern repeated.
The hardest level moves the gap off the end of the row. A gap at the end can be answered by continuing; a gap in the middle has to be read from both sides, which is the difference between copying a pattern and understanding it.