Eight number words down the left in rounded boxes, eight numerals in circles down the right, and a dot on each side to join with a pencil line. Six, two, nine, four, ten, one, seven, three.
Nothing has to be written, which is deliberate. A five year old who can recognize the word ten should not have to also form the numeral to prove it, and taking the writing out means the sheet tests one thing at a time.
The numerals on the right are deliberately out of order, so a child cannot work down both columns in step. Every word has exactly one numeral and every numeral has exactly one word, so the last one or two can be got by elimination, which is a real strategy rather than a loophole.
Nine and one are the pair that catch children out most, because both are short words that start with a letter they are still learning to tell apart.