Divisibility Tests

Can you tell whether a big number divides evenly by 9 without doing any long division? Divisibility rules give you quick shortcuts, and these quizzes turn them into instant checks.

Divisibility Rules and Quick Checks

You will choose numbers that divide cleanly and settle a few true or false claims, with prompts like which number is divisible by 4 or by 9. The first quiz sticks to the friendlier divisors, while the second pushes into tougher ones like 8, 11, 13, and 17, using multiple-choice and all-except style items.

The point is to lean on patterns instead of dividing the long way. A number like 124 is divisible by 4 because its last two digits, 24, are. These sets are pitched at an intermediate level and reward knowing the tests cold. Leaning on a rule instead of long division also makes you faster and far less likely to slip.

Did You Know?

The rule for 9 feels almost like magic. Add up all the digits, and if that sum divides by 9, the original number does too. The same trick works for 3, which makes those two among the easiest divisors to spot.

Eleven has a cleverer test. Alternately add and subtract the digits from left to right, and if you land on 0 or a multiple of 11, the whole number passes as well.

How the Quizzes Work

Each quiz is short, about five minutes, and you can repeat both as often as you like until the shortcuts come instantly. The more you use these rules, the faster you stop reaching for long division on numbers of any size. These shortcuts show up everywhere from simplifying fractions to spotting factors, so they are well worth memorizing. Ready to check divisibility at a glance? Open the free interactive math quizzes and start testing.