The fraction 7/20 as a decimal is 0.35. To calculate you can divide 20 by 100 to find out the decimal for 1/20, which equals 0.05, and then times this by the seven. Alternatively you can simply divide the seven by 20 to get the same result. Another way to calculate decimals would be to multiply the bottom fraction (in this case 20) by the number that would make it equal 100 (in this case five) Multiplying the top fraction by five will give the result 35/100. It is now easy to say that if the whole number is one, 35/100 of one would be 0.35.

So: What is the difference between decimals and fractions?

• Decimals are the numerical base that is most commonly used by modern civilizations. Decimal notation can refer to a base ten positional system, such as that used in the Hindu-Arabic numerical system, but is also used in a more general sense to refer to non positional systems such as Roman or Chinese numerals. Decimal fractions can also be referred to using the term 'decimals'. Within this context a decimal is a tenth part and all decimals are part of a series of nested tenths.

• In comparison, fractions are numbers that are expressed as the ratio of two numbers. These fractions are most commonly used to express a comparison between a whole and parts. The earliest fractions were ancient symbols that represented one part of two, one part of three, etc. Much later saw the introduction of the common or 'vulgar' fraction. These are still in use today and consist of a numerator and a denominator. For example, the common fraction 7/20 tells us that the numerator, seven, means that the fraction represents seven parts and the denominator, 20, tells us that 20 parts make up the whole.

So: What is the difference between decimals and fractions?

• Decimals are the numerical base that is most commonly used by modern civilizations. Decimal notation can refer to a base ten positional system, such as that used in the Hindu-Arabic numerical system, but is also used in a more general sense to refer to non positional systems such as Roman or Chinese numerals. Decimal fractions can also be referred to using the term 'decimals'. Within this context a decimal is a tenth part and all decimals are part of a series of nested tenths.

• In comparison, fractions are numbers that are expressed as the ratio of two numbers. These fractions are most commonly used to express a comparison between a whole and parts. The earliest fractions were ancient symbols that represented one part of two, one part of three, etc. Much later saw the introduction of the common or 'vulgar' fraction. These are still in use today and consist of a numerator and a denominator. For example, the common fraction 7/20 tells us that the numerator, seven, means that the fraction represents seven parts and the denominator, 20, tells us that 20 parts make up the whole.