Precision in mathematical language and notation

In maths, a good answer is an exact answer. If someone asks how long your pencil is, saying '18' is not enough. You need to say '18 centimetres'. The same care matters for fractions and symbols too.

The two numbers in a fraction each have a name. The top number is the numerator, and it counts the parts you have. The bottom number is the denominator, and it counts how many equal parts make the whole. Using the right name tells everyone exactly which number you mean.

Sometimes two fractions look different but cover the same amount. One third of a bar covers as much as two sixths of it. Fractions like 1/3 and 2/6 are called equivalent. Equivalent is the exact word, so use it instead of saying the two fractions are just the same.

Symbols must be exact too. Money uses the £ sign before the number and a decimal point, like £2.50, or a p after small amounts, like 75p. When you compare two numbers, use <, >, or =. The open side of > always faces the bigger number, so 5 > 2 reads as five is greater than two.