Number names up to 500 in class 2, and 'four hundred and seventy-three' takes him five minutes

He can count to a thousand, read any number you show him, add them happily. Ask him to write 473 in words and it's a five-minute job with three rubbings out and a meltdown somewhere around 'seventy'. The homework has ten of these a day. I know why they teach it. I just didn't expect spelling to be the hard part of maths 🙂 Did your kids get faster at this on their own, or did you end up drilling it?