A four by four grid of boxes, each holding a short coin sum like 10¢ + 10¢ + 5¢. The child adds every box and colors only the ones that come to exactly 25¢, which traces a path from START at the top left to FINISH at the bottom right. Moves go up, down, left or right, never diagonally.
The decoys are close on purpose: boxes worth 26¢ and 30¢ sit right beside the path, so one stray coin matters. Seven boxes make the path, and none of them uses a quarter, which is a quiet lesson in how many ways there are to make one.