# Pencil-and-paper arithmetic: are kids still supposed to be able to do it? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [March 22, 2026, 6:16pm UTC](https://boards.straightdope.com/t/pencil-and-paper-arithmetic-are-kids-still-supposed-to-be-able-to-do-it/1028688 "2026-03-22T18:16:47Z")\ **Posts on this page:** 1\ **Showing post:** 11
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 22, 2026, 8:01pm UTC](https://boards.straightdope.com/t/pencil-and-paper-arithmetic-are-kids-still-supposed-to-be-able-to-do-it/1028688/11 "2026-03-22T20:01:13Z")
It’s just a couple of multiplications. 16\*67 is the same as 16\*64 + 16\*3, or 1024 + 48, or 1072. 29\*37 is a little trickier, but it’s the same as 33^2 - 4^2. 33 is almost 1/3 of 100, so 33 squared is almost 1/9 of 10,000, which would be 1111… but it has to end in a 9, and be a multiple of 9, so it’s clearly 1089. 1089 - 16 is 1073. Since 37 \* 29 \> 16\*67, it follows that 29/67 \> 16/37. Although, those numbers are so close that I don’t think that’s coincidence, so that probably was the way that @Timz set up the problem. --- _[View the full topic](https://boards.straightdope.com/t/pencil-and-paper-arithmetic-are-kids-still-supposed-to-be-able-to-do-it/1028688)._