Three rows of bright pictures and three jobs. Circle the small ducks. Circle the big apples. Circle the small butterflies. Each row mixes big and small together, and there are three to circle in every row, so a child has to look along the whole line.
The instruction flips from small to big and back again, which catches the child who is circling on autopilot. It is worth reading each line aloud and pointing at the word SMALL or BIG as you go.
The butterfly row is the trickiest, because a couple of the bigger butterflies are close in size. The three small ones are still clearly the smallest, and spotting them takes a closer look than the ducks did.