Six empty boxes and a word under each one. If the word means one, the child draws one; if it means more than one, they draw more. Hearts gets several hearts, moon gets a single moon.
Drawing is a good check that the idea has really landed, because there is no word to copy and no picture to count. The child has to read the ending and decide.
Dress is the clever one here. It ends in s, but it is only one dress, and a child who has learned “s means more” will be tempted to draw a whole rack. Talking about it is a nice way into why dresses gets es.