Math Games: Numinja

Read the sum. Slice the answer.

Math Games: Numinja turns arithmetic practice into a fruit-slicing game. A question appears at the top, three numbered fruits fly up, and you swipe through the one that answers it. The right fruit builds your streak. A wrong fruit, or a wave you let fall, costs a heart and shows you the answer. You get three hearts.

WHY IT WORKS • Every question is written on the spot, so there is nothing to memorize • The wrong answers copy real mistakes, like a dropped carry or a swapped digit, so guessing costs you • Runs speed up gently after the first three waves, and the streak multipliers reward staying sharp • Mental arithmetic under a little time pressure is a different skill from arithmetic on paper, and this trains that one

FIVE TIERS Starter: adding and taking away within 20 Easy: two-digit sums, and the 2, 5 and 10 tables Medium: times tables to 12 × 12, division, three-digit sums Hard: two-digit multiplication, fractions, percentages, negatives Expert: big products by estimate, signed numbers, long division

A GENTLE START The first play is a three-swipe lesson with no hearts and no score. Results show what you got right, your accuracy and one question worth a second look.

BUILT FOR SHORT SESSIONS One thumb, portrait, and no sign-up: nothing to create, no password to remember. A run is a minute or two, Numinja keeps your best score for each tier on your phone, and it plays anywhere, with or without a connection.

Ads appear between runs. Reviving a finished run once is optional and ad-supported.

Discovery signals