Fast addition

SUMTHING

Something doesn't add up. Race the clock to solve addition problems in this fast-paced math game.

Beat the clock

Your best0

0correct

READY?

YOUR BEST0

How to play

Choose a difficulty and start the 60-second timer.
Find the missing number in each addition equation and submit your answer.
Keep solving until time runs out. Each correct answer adds to your score.

Easy high scores

Most correct answers in 60 seconds wins. One all-time best per player for each difficulty; equal scores share a rank. No sign-in is required; use Player name to set your name. Answers are checked on the server. Top 100 plus your own rank.

Rules, tips & more

Scoring & tips

Practice addition under pressure

SUMTHING is designed for quick number practice rather than long worksheets. Try a new difficulty, chase a personal best, or play without signing in to post an eligible score to the online high-score table.

Common questions

Is SUMTHING only addition? Yes. It focuses on finding missing numbers in addition problems, with Easy, Medium, and Hard difficulties.

Do I need to create an account? No. Browser players can post eligible online scores too. Set your public name with Account.

SUMTHING

Beat the clock

TIME!

Scoring & tips

Practice addition under pressure

Common questions