Blitz (Mind Loft)

Blitz is a ladder of twenty arithmetic problems done in your head. The five rounds start with two-digit addition and subtraction and the times tables, and work up to two-digit multiplication, awkward percentages, order of operations and cubes. Each problem has four answer buttons (keys 1 to 4 work too) and a fifteen-second clock.

The wrong options are chosen with care: each one is a mistake people really make, such as a dropped carry, the neighbouring row of the times table, reading a line left to right when precedence applies, or the cube next door. That means you cannot spot the right answer by its last digit or its size; you have to do the sum.

One wrong answer or an empty clock ends the run, and your score is how far up the ladder you got. Everyone plays the same twenty problems in the same order, so the leaderboard ranks the furthest run and breaks ties on time. Blitzed is the harder sibling, with three numbers on every line.