Numiro

Numiro is a free math practice site with two quite different audiences on one simple page: children building fluency in the four arithmetic operations, and calculus students who need a steady supply of integrals to work. It runs in the browser, and practice sessions open without an account.

On the arithmetic side there are separate practice sets for addition, subtraction, multiplication and division. Each session is ten questions, shown one at a time in large type with an on-screen number pad, and the answer is checked right away. An optional Arithmetic Calibration samples all four operations and gives each one its own skill rating, so a child who is quick at addition but slower at division gets problems at the right level for each. From then on the difficulty follows performance: get them right and the problems get harder.

The integration side is unusual for a free tool. Numiro generates antiderivative problems that range from powers, exponentials and trigonometric forms up to substitution, integration by parts, rational functions and partial fractions. The student builds the answer with a math keypad or by typing, with support for powers, roots, logarithms, trigonometric, inverse trigonometric and hyperbolic functions. Answers are checked by comparing derivatives, so any equivalent antiderivative is accepted and the constant of integration does not matter. That removes the usual frustration of a correct answer being marked wrong because it was written in a different form.

Both sides use the same loop: calibrate, practice, and watch a numerical rating and rank change over time. A free account adds a dashboard and saved progress, and there is a public leaderboard for students who like to compete. Families who prefer to skip the competitive side can simply use the practice pages.

Numiro is practice only. It does not teach the methods, show worked solutions or follow a curriculum, and it does not state grade levels, so pair it with whatever you use for instruction. Arithmetic practice suits roughly 2nd to 5th grade and anyone older who wants faster mental math. Integration practice suits a high school or college calculus student, including AP Calculus review. The site is free, supported by optional donations, and usage analytics are off unless you accept them.