Numbobulate

Numbobulate lays out four numbers in the corners of a square with the operations between them and a target in the centre, revealed when you tap it. Each daily game has three rounds. In each one you combine the corner numbers, using each at most once, to land exactly on the target. There are no brackets: the green equals box shows your running total after every step, so order matters.

The corner numbers stay fixed for a whole week and are always between 1 and 9. The targets are two-digit numbers and change every day. They started under 50 and have been creeping up toward 99, and one of the 29 October targets was 92. That gives the week a rhythm: by Sunday you know your four numbers well. If you get stuck, you can reset the round, and once all four numbers are used you can skip to the next one. At the end you get a result you can share, along with points for the day.

The daily rounds are served from the site by date, so everyone plays the same targets. The help screens include sample rounds on ideas like using three consecutive numbers, factoring and overshooting the target.

An answer one away from the target is accepted for fewer points, though every round has an exact solution. Speed counts. A correct round scores 2 points, plus a bonus point if you solve it within 9, 15 or 18 seconds. A Spicy setting gives you 90 seconds for all three rounds, and Family mode lets a few people play the same puzzle around one screen and keeps their tally for the week.

It suits players who like Countdown-style sums but want something shorter, with four small numbers in place of six.