Reading a marked position on a number line

Part of a number line is shown. The labelled marks are 3 and 4, and the smaller marks between them are equally spaced. What number does the arrow point to? Try it first. Pause if you like. Start with the labelled marks 3 and 4. Their difference is 4 minus 3, which is 1. Count the small gaps from 3 to 4. One, two, three, four, five. Count the spaces, not the marks. Divide the difference by the 5 gaps. 1 divided by 5 is zero point two, so one small gap is zero point two. Start at 3 and count the small gaps to the arrow. One, two, three. 3 small gaps are 3 times zero point two, which is zero point six. So the reading is three point six.

Part of the scale on a luggage weighing machine is shown. It is labelled at every 2 kilograms, and the smaller marks between the labels are equally spaced. What mass does the pointer show? Try it first. Pause if you like. Start with the labelled marks 6 kilograms and 8 kilograms, on either side of the pointer. Their difference is 8 minus 6, which is 2 kilograms. Count the small gaps from 6 kilograms to 8 kilograms. One, two, three, four, five, six, seven, eight. Count the spaces, not the marks. Divide the 2 kilograms by the 8 gaps. 2 divided by 8 is zero point two five, so one small gap is zero point two five kilograms. Start at 6 kilograms and count the small gaps to the pointer. One, two, three. 3 small gaps are 3 times zero point two five, which is zero point seven five kilograms. So the pointer shows six point seven five kilograms. Find what one small gap is worth, then count on the gaps from a labelled mark.