# How Do You Read A Mm Ruler?

The markings on a millimetre ruler are such that it is not hard at all to take the measurements to one decimal place. Whether it is a 15, 30 or 100-centimetre ruler, it is much the same case with every ruler. The 10 indentations between each centimetre denote each millimetre, of which there are ten in every one centimetre. Every fifth millimetre is seen to be longer than the first, second, third, fourth, sixth, seventh, eighth and ninth. This is to make markings of every half-centimetre easier to read. An object 8.5cm long has 85 millimeters. It is easier to count in centimetres, then work out the decimal point of the last centimetre value by means of looking at the marking on the ruler; if it comes up to the fifth marker of that set of 10 millimetres, the decimal is .5. These rulers are useful in architecture to get exact measurements without rounding up or down to the nearest centimetre, which of course you can do with the millimetre ruler; you round up if it goes beyond or is on the .5 marker, and down if it is below it. It is thus very easy to read a mm ruler.
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