What are fractions?
Fractions are numbers that express a part of a whole. A fraction consists of a numerator (top number) and a denominator (bottom number). For example, in the fraction 3/4, the numerator is 3 and the denominator is 4. Fractions are used in mathematics, cooking, construction and many other areas.
How to add and subtract fractions?
To add or subtract fractions, find a common denominator. For example, 1/2 + 1/3: the common denominator is 6, so 3/6 + 2/6 = 5/6. Subtraction works the same way: 3/4 – 1/3 = 9/12 – 4/12 = 5/12.
How to multiply and divide fractions?
Multiplication: Multiply numerators together and denominators together. For example, 2/3 × 3/4 = 6/12 = 1/2.
Division: Flip the second fraction and multiply. For example, 1/2 ÷ 3/4 = 1/2 × 4/3 = 4/6 = 2/3.
How to simplify a fraction?
Simplify a fraction by dividing the numerator and denominator by their greatest common divisor (GCD). For example, 6/9: GCD(6,9) = 3, so 6/9 = 2/3. A simplified fraction is the simplest expression of the same value.
What is a mixed number?
A mixed number consists of a whole part and a fraction, for example 2 1/3. To convert a mixed number to an improper fraction: multiply the whole part by the denominator and add the numerator. For example, 2 1/3 = (2×3+1)/3 = 7/3.
How to convert a fraction to a decimal?
To convert a fraction to a decimal, divide the numerator by the denominator. For example, 3/4 = 3 ÷ 4 = 0.75. Conversely, a decimal can be converted to a fraction: 0.75 = 75/100 = 3/4.
Fraction calculation examples
Recipe: A recipe calls for 2/3 cup of flour. You want to make half the recipe: 2/3 × 1/2 = 2/6 = 1/3 cup.
Construction: A board is 3/4 metre long. You need to cut off 1/3 metre: 3/4 – 1/3 = 9/12 – 4/12 = 5/12 metre remaining.