Answer:

We need standard unit for measurement to make our judgement more reliable and accurate. For proper dealing, measurement should be same for everybody. Thus there should be uniformity in measurement. For the sake of uniformity we need a common set of units of measurement, which are called standard units. Nowadays Si units in science and technology almost accepted universally.

Knowing the units of measurement that correspond with a number can give you so much more information than a digit sitting there by itself. Units can: Help to show another person the exact amount you have