romerska siffror XXI

I 1
II 2
III 3
IV 4
V 5
VI 6
VII 7
VIII 8
IX 9
X 10
XI 11
XII 12
XIII 13
XIV 14
XV 15
XX 20

XXX 30
XL 40
L 50
LX 60
LXX 70
LXXX 80
XC 90
C 100
CL 150
CC 200
D 500
DC 600
M 1000
MCMLXXV 1975
MCMXC 1990
MM 2000
MMX 2010
MMXV 2015
MMXX 2020
MMXXI 2021
MMXXII 2022
MMXXIII 2023
MMXXIV 2024
MMXXV 2025 

1-100

1 = I = 1
2 = II = 1 + 1
3 = III = 1 + 1 + 1
4 = IV = 5 − 1
5 = V = 5
6 = VI = 5 + 1
7 = VII = 5 + 1 + 1
8 = VIII = 5 + 1 + 1 + 1
9 = IX = 10 − 1
10 = X = 10
11 = XI = 10 + 1
12 = XII = 10 + 1 + 1
13 = XIII = 10 + 1 + 1 + 1
14 = XIV = 10 + 5 − 1
15 = XV = 10 + 5
16 = XVI = 10 + 5 + 1
17 = XVII = 10 + 5 + 1 + 1
18 = XVIII = 10 + 5 + 1 + 1 + 1
19 = XIX = 10 + 10 − 1
20 = XX = 10 + 10
21 = XXI = 10 + 10 + 1
22 = XXII = 10 + 10 + 1 + 1
23 = XXIII = 10 + 10 + 1 + 1 + 1
24 = XXIV = 10 + 10 + 5 − 1
25 = XXV = 10 + 10 + 5
26 = XXVI = 10 + 10 + 5 + 1
27 = XXVII = 10 + 10 + 5 + 1 + 1
28 = XXVIII = 10 + 10 + 5 + 1 + 1 + 1
29 = XXIX = 10 + 10 + 10 − 1
30 = XXX = 10 + 10 + 10
31 = XXXI = 10 + 10 + 10 + 1
32 = XXXII = 10 + 10 + 10 + 1 + 1
33 = XXXIII = 10 + 10 + 10 + 1 + 1 + 1
34 = XXXIV = 10 + 10 + 10 + 5 − 1
35 = XXXV = 10 + 10 + 10 + 5
36 = XXXVI = 10 + 10 + 10 + 5 + 1
37 = XXXVII = 10 + 10 + 10 + 5 + 1 + 1
38 = XXXVIII = 10 + 10 + 10 + 5 + 1 + 1 + 1
39 = XXXIX = 10 + 10 + 10 + 10 − 1
40 = XL = 50 − 10
41 = XLI = 50 − 10 + 1
42 = XLII = 50 − 10 + 1 + 1
43 = XLIII = 50 − 10 + 1 + 1 + 1
44 = XLIV = 50 − 10 + 5 − 1
45 = XLV = 50 − 10 + 5
46 = XLVI = 50 − 10 + 5 + 1
47 = XLVII = 50 − 10 + 5 + 1 + 1
48 = XLVIII = 50 − 10 + 5 + 1 + 1 + 1
49 = XLIX = 50 − 10 + 10 − 1
50 = L = 50
51 = LI = 50 + 1
52 = LII = 50 + 1 + 1
53 = LIII = 50 + 1 + 1 + 1
54 = LIV = 50 + 5 − 1
55 = LV = 50 + 5
56 = LVI = 50 + 5 + 1
57 = LVII = 50 + 5 + 1 + 1
58 = LVIII = 50 + 5 + 1 + 1 + 1
59 = LIX = 50 + 10 − 1
60 = LX = 50 + 10
61 = LXI = 50 + 10 + 1
62 = LXII = 50 + 10 + 1 + 1
63 = LXIII = 50 + 10 + 1 + 1 + 1
64 = LXIV = 50 + 10 + 5 − 1
65 = LXV = 50 + 10 + 5
66 = LXVI = 50 + 10 + 5 + 1
67 = LXVII = 50 + 10 + 5 + 1 + 1
68 = LXVIII = 50 + 10 + 5 + 1 + 1 + 1
69 = LXIX = 50 + 10 + 10 − 1
70 = LXX = 50 + 10 + 10
71 = LXXI = 50 + 10 + 10 + 1
72 = LXXII = 50 + 10 + 10 + 1 + 1
73 = LXXIII = 50 + 10 + 10 + 1 + 1 + 1
74 = LXXIV = 50 + 10 + 10 + 5 − 1
75 = LXXV = 50 + 10 + 10 + 5
76 = LXXVI = 50 + 10 + 10 + 5 + 1
77 = LXXVII = 50 + 10 + 10 + 5 + 1 + 1
78 = LXXVIII = 50 + 10 + 10 + 5 + 1 + 1 + 1
79 = LXXIX = 50 + 10 + 10 + 10 − 1
80 = LXXX = 50 + 10 + 10 + 10
81 = LXXXI = 50 + 10 + 10 + 10 + 1
82 = LXXXII = 50 + 10 + 10 + 10 + 1 + 1
83 = LXXXIII = 50 + 10 + 10 + 10 + 1 + 1 + 1
84 = LXXXIV = 50 + 10 + 10 + 10 + 5 − 1
85 = LXXXV = 50 + 10 + 10 + 10 + 5
86 = LXXXVI = 50 + 10 + 10 + 10 + 5 + 1
87 = LXXXVII = 50 + 10 + 10 + 10 + 5 + 1 + 1
88 = LXXXVIII = 50 + 10 + 10 + 10 + 5 + 1 + 1 + 1
89 = LXXXIX = 50 + 10 + 10 + 10 + 10 − 1
90 = XC = 100 − 10
91 = XCI = 100 − 10 + 1
92 = XCII = 100 − 10 + 1 + 1
93 = XCIII = 100 − 10 + 1 + 1 + 1
94 = XCIV = 100 − 10 + 5 − 1
95 = XCV = 100 − 10 + 5
96 = XCVI = 100 − 10 + 5 + 1
97 = XCVII = 100 − 10 + 5 + 1 + 1
98 = XCVIII = 100 − 10 + 5 + 1 + 1 + 1
99 = XCIX = 100 − 10 + 10 − 1
100 = C = 100 

Förklaring av romerska siffror

De sju romerska siffrorna är: I=1, V=5, X=10, L=50, C=100, D=500, och M=1000. Istället för positionsprincipen använde romarna antingen additions- eller subtraktionsprincipen. Det krävdes fyra tecken för att skriva 8, det vill säga V+I+I+I och två tecken för att skriva 4, IV, vilket betyder V-I.

Kort lista med romerska siffror

1. I = 1.
2. V = 5.
3. X = 10.
4. L = 50.
5. C = 100.
6. D = 500.
7. M = 1000.

Hut romarna räknade

Romarna använde istället en abacus – ett slags kulram. Romarnas talsystem bestod av bokstäver, som symboliserade positiva, hela tal, till exempel I=1, X=10, C=100, M=1000, medan V=5, L=50 och D=500