Mental Math Battle
Mental Math Battle is a mental arithmetic game where you choose the answer to each problem from four options and defeat book monsters with magic. It is free, needs no account, and runs in your browser on a computer or smartphone.
How to play
- Choose a problem type: addition, subtraction, multiplication, division, or mix (all four). Rankings are separate for each type.
- A sheet of magic paper floats in front of the hero with a problem on it. Pick the answer from the four choices below by clicking, tapping, or pressing keys 1–4.
- A correct answer makes the hero cast a spell at the monster. The answer itself is the damage, and the monster loses that much health. When a monster is defeated, the next one appears.
- A wrong answer, or letting the fuse under the paper burn out (time up), lets the monster attack and costs one life. You have three lives; the game ends when they run out.
- Problems keep coming until you are out of lives. Press Esc to pause.
Difficulty and time limit
| Step | Addition | Subtraction | Multiplication | Division |
|---|---|---|---|---|
| 1 (questions 1–8) | 1 digit + 1 digit | 1-digit answer | Times tables (2–5) | Reverse tables (÷2 to ÷5) |
| 2 (questions 9–16) | 2 digits + 1 digit | 2 digits − 1 digit | Times tables | Reverse tables |
| 3 (questions 17–24) | 2 digits + 2 digits | 2 digits − 2 digits | Two products like 1×2+3×3 | 2 digits ÷ 1 digit |
| 4 (questions 25–32) | Three numbers | a−b−c, a+b−c | Two products (2–9) | Division plus addition |
| 5 (question 33 on) | With 3 digits | With 3 digits | a×b+c×d−e | Sum of two divisions |
- Order of operations: Multiplication and division come first.
- Time limit: 10 seconds at first, shrinking smoothly with each question to 2 seconds at question 45.
- Choices: The wrong choices are common mistakes (off by 1 or 10, a neighboring times table, the result of the wrong order of operations, and so on). All choices are different positive integers.
Score and streaks
- Score: Base points × speed bonus × streak multiplier.
- Base points: 100, 150, 220, 320, and 450 for steps 1 to 5.
- Speed bonus: 2x for an instant answer, 1x at the last moment.
- Streak multiplier: Rises by 0.1x per answer from the second correct answer in a row, up to 5x. A miss resets the streak to 0.
- Spell steps: At streaks of 5, 10, 20, 30, and 50, the spells get brighter, bigger, and flashier.
Monsters and rankings
- Monsters: A Flying Book, an Ink Slime, and a Scroll Ghost appear in turn, and the big Grimoire King appears as the seventh. After that, the Grimoire King appears as one in every three monsters, and each round of monsters gets a little tougher. A monster’s health is set from the size of the answers at the time it appears (harder problems have bigger answers and tougher monsters).
- Rankings: For each problem type, the top 50 players’ personal bests are shown. You can open them from the title screen and the result screen.
- Record check: When you start, the server issues a ticket and the seed for the problems. When the game ends, your answers are sent. The server rebuilds the same problems, checks the answers and whether the answer times are humanly possible, then recalculates the score before recording it.
FAQ
Is it free?
Yes. It is free and needs no account. Your ranking entry uses the guest name tied to this device.
Can I play on a smartphone?
Yes. In portrait mode, the answer buttons are shown large below the scene. On a computer you can click or press keys 1–4.
How hard does it get?
Problems get harder in five steps as you answer more, and the time limit shrinks smoothly from 10 seconds to 2 seconds by question 45. After that it stays at 2 seconds.
How is the score calculated?
Each answer scores base points for its difficulty, multiplied by a speed bonus based on the time left (1x to 2x) and a streak multiplier (+0.1x per answer, up to 5x). The server recalculates the score before recording it.