SumSurf is a retro-synthwave maths game where every wave is a question. Drop in at the setting sun, read the sum glowing on its face, and carve down the water past speedboats, jetskis, shark fins, swimmers and rocks. Then steer into the bubble holding the right answer before your board hits the sand. Wrong bubbles and crashes cost hearts; right answers build a streak multiplier worth up to five times the points. Three levels grow with the player: GROM (ages 4–7), SURFER (8–11) and PRO (12–16), each with stages of ten waves. Clear them all to be crowned CHAMPION.
Players build fast, accurate recall under gentle time pressure. GROM players continue counting sequences (skip-counting in 2s, 5s and 10s), add and subtract within 20, double numbers and meet early times tables. SURFER players practise times tables to 12 and division facts, add and subtract to 100, square numbers and apply the order of operations. PRO players solve linear equations, work with negative numbers, find fractions and percentages of amounts, and evaluate expressions with brackets. The wrong answers are near-misses, such as off-by-one, swapped digits and flipped signs, so players have to calculate rather than guess. Teachers can track accuracy, response time and mastery for each question and skill through xAPI.
Teachers can test (free play), assign and purchase games for their classes after signing in.