Roman numerals · Usually met around P3
Roman numerals: no zero, no place value
Ours use place; Roman numerals use letters.
How to do it
Method
Ours use place; Roman numerals use letters
305: 3 hundreds, 0 tens, 5 ones = CCCV
Another way
Pool the letters
XII + XIII → XXIIIII → XXV = 25
In full
Our numerals use just ten digits, 0 to 9, and the same digit means a different value in a different place: the three 3s in 333 are 300, 30 and 3. An empty place needs a 0 to hold it: 305 is not 35. Roman numerals have no place value: each letter has its own fixed value, so they need no zero, and an empty group is simply left out: 305 = CCCV. For working things out, our numerals line up in columns and add place by place. Roman numerals don't line up, so the Romans pooled the letters and tidied them (five I's into a V, two V's into an X…) or used a counting board. That is why our numerals are far easier to calculate with.
Worked examples
Have a go first, then open each one for the answer and the working.
Example 1
The tablet shows 1400 in Roman numerals. 1400 has □ thousands, □ hundreds, □ tens and □ ones.
Fill in each box
Show the answer and working
Answer: 1，4，0，0
Two of 1400's places are 0: we write 0s to hold them, while the Roman numeral simply leaves those groups out.
Example 2
Writing 1009, we need a 0 to hold the empty place. The tablet shows 1009 in Roman numerals. How many letters does it use?
Show the answer and working
Answer: 3
An empty group is left out and only the others are written: 3 letters in all.
Example 3
909 has two 9s in it. The left 9 stands for how many times as much as the right 9?
- A. 10
- B. 100
- C. 1000
- D. 1
Choose the right answer
Show the answer and working
Answer: B. 100
The left 9 stands for 900 and the right one for 9: 900 is 100 times 9.
Practise it in the game →Roman numerals · Free to start, unlimited questions, no download