Roman Numerals

1
Roman Numerals

• Learning objective
• To learn how to count using Roman numerals.

2

• The Romans did not have separate characters for
  numbers as we do today. Instead they used
  letters to symbolise different numbers.

3
What were the Roman numerals?
1 I 9 IX 60 LX
2 II 10 X 70 LXX
3 III 11 XI 80 LXXX
4 IV 12 XII 90 XC
5 V 20 XX 100 C
6 VI 30 XXX 500 D
7 VII 40 XL 1,000 M
8 VIII 50 L
(the Romans did not have a character for zero) (the Romans did not have a character for zero) (the Romans did not have a character for zero)
4
Write out the following numbers in Roman numerals

• 21
• 29
• 19
• 6
• 45

5
Write out the following numbers in Roman numerals

• 21 XXI
• 29
• 19
• 6
• 45

6
Write out the following numbers in Roman numerals

• 21 XXI
• 29 XXIX
• 19
• 6
• 45

7
Write out the following numbers in Roman numerals

• 21 XXI
• 29 XXIX
• 19 XIX
• 6
• 45

8
Write out the following numbers in Roman numerals

• 21 XXI
• 29 XXIX
• 19 XIX
• 6 VI
• 45

9
Write out the following numbers in Roman numerals

• 21 XXI
• 29 XXIX
• 19 XIX
• 6 VI
• 45 XLV

10
What are these numbers?

• XXIII
• CL
• CI
• LVII
• LXVI

11
What are these numbers?

• XXIII 23
• CL
• CI
• LVII
• LXVI

12
What are these numbers?

• XXIII 23
• CL 150
• CI
• LVII
• LXVI

13
What are these numbers?

• XXIII 23
• CL 150
• CI 101
• LVII
• LXVI

14
What are these numbers?

• XXIII 23
• CL 150
• CI 101
• LVII 57
• LXVI

15
What are these numbers?

• XXIII 23
• CL 150
• CI 101
• LVII 57
• LXVI 66

16
Change the Roman numerals below to our numbers

• X
• VIII
• XIII
• D
• LVII
• XCI
• LXV
• XXXIII

• XLV
• LXXXVI

17
Now change the following to Roman numerals

• 3
• 6
• 14
• 27
• 38
• 55
• 87

• 91
• 503
• 197
• 363

18
Now do these Roman sums
I II XX VIII
V V IX IX
V IV X IV XXIII IX L IV
X V CI XI
IV VIII 13. L II
X XII 14. LXXII XIV



19
Now answer this question

• Why do you think we no longer use Roman numerals
  today?