roman numbers

Sunday evening? Already? Well that still leaves time for a quick entry on Roman numerals. This is a cut out and keep entry written with you in mind Rose. Read it, and you’ll finally be able to work out the date on that aquarium.

Firstly then, the real basics. I is the smallest whole number. It represents one unit. If you place 2 equal units next to each other, you add their value together. II = 2 therefore, and III = 3. The next symbol is V, which represents 5 units. If you put a number to the left of a bigger one, you subtract the smaller number. i.e. IV = V (5 units) – I (one unit) = 4. If the numbers are written the other way around (big number followed by smaller), you add them together: VI = V + I = 6.

The next symbol we need to know is X, which means 10. Using the principles above, XX must equal 20, IX 9 and XI 11. As a point of interest, these numerals seem to have developed from counting on fingers. I was supposed to represent 1 finger, V the shape made by the thumb and fingers when you hold them all out and X is 2 hands crossed over.

The other symbols we need are L for 50, C for 100, D or I‘backwards C’ for 500 and M or CI’backwards C’ for 1000.

A few more principles to work with:

1. A line above the number multiplies by 1, 000: II = 2, Ī Ī = 2,000

2. ‘backwards C’ to the right of I’backwards C’ multiplies the figure by 10.

E.g. I’backwards C’ ‘backwards C’ = 5,000, e.g. 2 I’backwards C’ ‘backwards C’ ‘backwards C’ = 50, 000.

3. C in front of the I (repeated as many times as ‘backwards C’ follows) doubles the number. E.g. I’backwards C’ ‘backwards C’ = 5, 000 but CCI’backwards C’’backwards C’ = 10, 000

A bit of a drily technical post I’m afraid, but I hope it helps.

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