 What is a decimal? The word decimal describes something which is based on a system of tens. Decimals are numbers like 23.4, 0.7 and 4.257. Any digits to the right of the decimal point are parts of the number which are less than one. Using paper or card, cut out some cards containing the fractions and decimals. Use a ruler to create a strip with 10 equal parts. This will be the number line. Place the fractions on the number line and encourage your child to place the decimal cards on the correct corresponding fraction.