Roman numerals · Usually met around P3
Converting and comparing Roman numerals
Change to our numerals first, then compare.
How to do it
Method
Change to our numerals first, then compare
VIII = 8 < IX = 9
Another way
Biggest group first
MCD vs MCC: same thousands, CD = 400 > CC = 200
In full
Roman to our numerals: split the letters into thousands, hundreds, tens and ones, read each group and add; or go left to right, taking away a smaller letter before a bigger one. Our numerals to Roman: write place by place, and write nothing for a 0: 307 = CCC + VII = CCCVII. To compare two Roman numerals, never go by how many letters: VIII has four letters but is smaller than IX, which has two. Change both to our numerals and compare; or compare the biggest group first: the thousands' M's, then the hundreds if those match, and so on.
Worked examples
Have a go first, then open each one for the answer and the working.
Example 1
The number on the left tablet is bigger than the one on the right.
True or false?
Show the answer and working
Answer: True
In our numerals the left is 97 and the right is 72. Don't go by how many letters.
Example 2
How many of the four tablets show a number bigger than 1699?
Show the answer and working
Answer: 0
Change each to our numerals: 1074, 1182, 1480, 1151. 0 of them are bigger than 1699.
Example 3
Of the three tablets' numbers, the biggest is □ and the smallest is □.
Fill in each box
Show the answer and working
Answer: 279，10
Change each to our numerals: 89, 279, 10. Biggest 279, smallest 10.
Practise it in the game →Roman numerals · Free to start, unlimited questions, no download