Equivalent fractions, simplifying and ordering, adding and subtracting (mixed numbers too), and fractions of amounts.
What you will learn
- Simplify and order fractions
- Add and subtract fractions and mixed numbers
- Find a fraction of an amount
- Write one quantity as a fraction of another
Equivalent fractions and simplifying
In a fraction such as 3/4, the top number is the numerator and the bottom number is the denominator: the denominator says how many equal parts the whole is cut into, and the numerator how many of them you have.
Multiplying or dividing the top and the bottom by the same number gives an equal fraction: 3/4 = 6/8 = 15/20.
To simplify, divide both by their highest common factor: 18/24 = 3/4 (÷ 6). A fraction is in its simplest form when the top and bottom have no common factor but 1.
To fill a gap, as in 2/5 = □/20, see what the known bottom was multiplied by (5 × 4 = 20) and do the same to the top: 2 × 4 = 8, so 2/5 = 8/20.
To compare or order fractions, write them over a common denominator (a denominator both can be written with): 2/3 = 8/12 and 3/4 = 9/12, so 3/4 is bigger.
The rest of this lesson and its 7 practice questions are locked.
In this lesson
- Equivalent fractions and simplifying
- Adding and subtracting
- A fraction of an amount
- Try it: Check with the fraction calculator
7 practice questions, marked as you go; about 25 minutes in all.
Key terms
Numerator, Simplest form, Mixed number, Improper fraction
In this unit: Fractions, decimals and percentages
Calculate with fractions and mixed numbers, move between fractions, decimals and percentages, and solve percentage problems, including reverse percentages.