Speed Math Quiz

How a round works

Press “Start” and a 60-second clock begins while the first equation appears. Type your answer and press Enter (or the Submit button); it is graded immediately and the next question replaces it. A correct answer adds one to your count. A wrong answer costs no points, but it uses up time you could have spent on the next question, so your result is really accuracy multiplied by speed. If you submit with the box empty, nothing happens and the same question stays, so you cannot skip. When the round ends, every miss is listed with the right answer so you can review it. The clock is based on the start time rather than on counting ticks, which means the round still ends at 60 seconds even if you switch tabs.

What range do the questions come from?

The four operations are drawn with equal probability (one in four each), and each has its own number range. The table below is calculated by enumerating the generator rules used by this page’s script. Division questions are built by choosing the divisor and quotient first and multiplying them to get the dividend, so there is never a remainder; the largest dividend you can see is 132.

Averaged over the four operations, about 37.3% of questions have a one-digit answer. In other words, most answers have two or more digits, and addition almost never gives a single digit. The 144 products on a 12 x 12 times table contain only 59 distinct values, so you will meet the same product through different equations again and again. Subtraction picks the second number evenly from 0 up to the first, so an answer of 0 can occur. Negative answers never appear.

Turning your score into a pace

Attempting N questions in 60 seconds means 60 / N seconds per question. Wrong answers also consume time, so the fair measure is questions attempted, not questions correct.

Typing and submitting also take time, so the real thinking time is shorter than the table suggests. To pass 20 questions you must finish calculating and typing in 3 seconds each; for 30 questions, in 2 seconds. Use the table to set goals. This page does not claim an “average” score for anyone, because it has no data on that.

Mental math tricks with checked examples

• Addition: round one number to a multiple of ten, then add the rest. 38 + 47 is 38 + 40 = 78, plus 7 = 85. Adding the units first gives the same answer (8 + 7 = 15, then 30 + 40 + 15 = 85).
• Subtraction: take away a rounder number and correct. 83 − 47 is 83 − 50 = 33, then add 3 back for 36. This avoids borrowing from the tens column.
• Multiplication: the times tables here go beyond 9, up to 12. Split the 12 times table into 10 times plus 2 times: 12 × 7 = 70 + 14 = 84. For 7 × 8 = 56, the digits 5, 6, 7, 8 appear in order, a handy memory hook.
• Division: think of it as a missing factor. 96 ÷ 8 asks what times 8 gives 96; 8 × 12 = 96, so the answer is 12. Quotients here stop at 11, so 132 ÷ 12 = 11 is the largest case.
• Nines check: the digits of 9 × 1 through 9 × 10 always add up to 9 (9 × 7 = 63, 6 + 3 = 9), a quick sanity check on a product. 9 × 11 = 99 is the exception, with digit sum 18.

The 11 and 12 times tables are the part many people never memorised. For 11 times a one-digit number the digit repeats (11 × 7 = 77). For 11 times a two-digit number, place the sum of the digits between them (11 × 12: 1, 1 + 2, 2, giving 132). The 12 times table is 10 times plus 2 times.

Common mistakes

• Subtracting in the wrong order. In this game the first number is always at least as large as the second, so the answer is never negative. If you got a negative number, you flipped the subtraction.
• Expecting remainders. Division here always comes out even, so you never need a decimal or a fraction.
• Dropping a digit while typing in a hurry, or reaching for the mouse instead of pressing Enter. If you compare scores, keep the same input method each time.
• Typing a decimal such as 3.5. Every correct answer is a whole number, so a decimal is always counted as wrong.

Getting more out of the game

• Find your weak operation. The review list shows your misses. Repeated errors on × and ÷ point to the times tables; errors on − point to rounding practice.
• Use it as a one-minute warm-up before work or a test. It is a light exercise for number sense; this page does not cite any study measuring its effect.
• For times tables only, use the multiplication table practice; for percentage questions in daily life, try the percentage calculator.

A sensible practice order

Start with accuracy, not speed. Until your accuracy is reliably above 90%, do not push for faster rounds. If the same kind of equation keeps showing up in the review list, drill that operation separately, and only then work on cutting the average seconds per question. Scores vary with mood and input method, so judge the trend over several rounds, not a single result.

Best score storage and limits

Your best score (number correct) is saved in this browser’s localStorage under the key speed-math-best when a round ends. It is not uploaded to a server and does not follow you to another device or browser; clear the site data in your browser settings to remove it. Difficulty is fixed, so questions do not get harder as you improve. Questions come from Math.random, so the same question can appear twice in a row (this is not a randomness source for exams or draws).

Frequently Asked Questions