Left the last section blank in three final exams. He says he ran out of time

Our elder son's class 5 papers came back with the report card, and in maths, science and social the last section is simply empty. He isn't weak in any of them. He says he writes slowly because he wants it neat, and by the time he got to the end the bell had gone. I don't want to turn his summer into timed practice papers, not with a toddler running around the house. Is there something lighter that helps a 10 year old judge his time in an exam?