A selection of free mathematical resources (calculators, exercises, games, quizzes, course reminders) to learn how to calculate with different types of numbers.

## Numbers : Reminder

### Prime numbers

A prime number is an integer greater than or equal to 2 that has no divisors other than 1 and itself.

#### Decomposition in product of primes

Any integer greater than or equal to 2 is prime or product of primes.
When we write an integer as a product of prime numbers, we say that we decompose this integer into a product of prime numbers.

### Percentage

A percentage is defined as a proportionality coefficient expressed as a fraction with a denominator of 100.

To calculate p% of a number is to multiply that number by p/100.

### Euclidean division

Performing Euclidean division of a by b, is equivalent to determining two numbers, the quotient (q) and the remainder (r) such that a = b*q + r .

## Numbers : games and quizzes

• game about area calculations of usual figures. (numbers): This game allows you to practice the calculation of simple surfaces: square, rectangle, circle.
• Duration calculation game (numbers): This game on time calculations allows to practice manipulating durations expressed in days, hours, minutes, seconds (d, h, min, s).
• math game with integers (numbers): In this calculation game with integers, kids must find the right answer in a list of values.
• Quiz on the calculation of the GCD (numbers): This Greatest Common Divisor quiz gives practice in calculating the GCD of two integers.
• Calculation game percentages (numbers): To succeed in this game on the calculation of the percentage of a whole number, kids must choose the good answer among a list of proposition.
• magic square game (numbers): The goal of the game is to complete a magic square that has empty areas.
• Measurement conversion game (numbers): This math game allows you to practice converting length and area measurements.
• time conversion game (numbers): This game allows you to practice making conversions on days, hours, minutes, seconds (d, h, min, s).
• find the denominator game (numbers): In this fraction game, children must complete an equality involving a fraction by finding the missing denominator in a list.
• division game (numbers): Online game of calculation, which allows practicing integer division.
• criteria divisibility game (numbers): Online calculation game, which allows to train to recognize if a number is divisible by 2, 3, 4, 5, 9, 10, 25, 100.
• fraction game (numbers): Online fraction game suitable for anyone looking for a good math game online.
• Fraction calculation game (numbers): This math game is based on the calculation of whole fractions. To win this quiz, you just have to find the result of an operation between two fractions.
• fraction comparison game (numbers): The purpose of this integer fraction comparison game is to find the operator (> or <) to place between the fractions being compared.
• irreducible fraction of an expression (numbers): To pass this quiz on irreducible fractions, you just have to find the irreducible form of an operation between several fractions.
• Fraction to percentage transformation game (numbers): In this game of transforming a whole fraction into a percentage, children must choose the correct answer from a list of suggestions.
• countdown game (numbers): The goal of the countdown maths game is to find a target number using arithmetic operations from a list of given numbers.
• multiplication game (numbers): The goal is to choose from a list the multiplication that allows to calculate a given number online.
• Game multiplication by 10, 100, 1000 or 0.1, 0.01, 0.001 (numbers): The goal of this quiz is to multiply a number by 10, 100, 1000 or 0.1, 0.01, 0.001. To win this game, you just have to find the right result in a list.
• number comparison game (numbers): The goal of this integer comparison game is to find the operator (less than, greater than or equal to) to place between the numbers being compared.
• missing number game (numbers): Online calculation game: You must find the missing number in a mathematical expression.
• perimeter game (numbers): This game allows you to practice calculating perimeters on common shapes: square, rectangle, triangle, circle.
• the little math quiz (numbers): The little math quiz collects a set of small fun math exercises to do online for 7-11 year olds.
• proportionality game (numbers): The goal of this proportionality game is to find the value that completes a proportionality table.
• Quiz on the Pythagorean theorem (numbers): This quiz uses the Pythagorean theorem to calculate the hypotenuse of a right triangle.
• four operations game (numbers): This online game of mental calculation, allows to revise addition, subtraction, multiplication and division, It helps students in learning arithmetic operations.
• missing operator game (numbers): Online calculation game consisting of finding the missing operator in a mathematical expression.
• addition tables game (numbers): Addition tables game to learn, revise, memorize addition tables from 1 to 20 online.
• times tables game (numbers): Times tables game to revise and learn multiplication tables from 1 to 10 online.
• Subtraction tables game (numbers): Online mental calculation game to help to memorize the subtraction tables.
• three operations game (numbers): Online mental calculation game, allows to review addition, subtraction and multiplication, this game helps students to practise arithmetic operations.