Weights And Numbers

You should also know how to estimate weights-a letter of an ounce, or a fish or a potato of one pound, or a sack of bran, and also the probable weight of a man from his appearance. These, again, are only learnt by practice. Learn also to judge numbers-to tell at a glance approximately how many people are in a crowd, or on a bus, or in a big crowd; how many sheep in a flock; how many marbles on a tray, and so on. You can practise for yourself at all times in the street or field.