The divisibility rules of 1 to 100
1: Every number is a multiple of 1
2: The number ends in 0, 2, 4, 6 or 8 (an even digit)
3: The sum of the digits is a multiple of 3
4: The 2nd to last digit is even and the last digit is 0, 4 or 8, or the 2nd to last digit is odd and the last digit is 2 or 6
5: The number ends in 0 or 5
6: The number is a multiple of both 2 and 3
7: The subtraction of twice the last digit and the rest of the number is a multiple of 7
8: The 3rd to last digit is even and the last 2 digits are a multiple of 8 or the 3rd to last digit is odd and the last 2 digits are a multiple of 4 but not of 8
9: The sum of the digits is a multiple of 9
10: The number ends in 0
11: The subtraction of the sum of the digits in odd places and the sum of the digits in even places is a multiple of 11
12: The number is a multiple of both 3 and 4
13: The sum of 4 times the last digit and the rest of the number is a multiple of 13
14: The number is a multiple of both 2 and 7
15: The number is a multiple of both 3 and 5
16: The 4th to last digit is even and the last 3 digits are a multiple of 16 or the 4th to last digit is odd and the last 3 digits are a multiple of 8 but not of 16
17: The subtraction of 5 times the last digit and the rest of the number is a multiple of 17
18: The number is a multiple of both 2 and 9
19: The sum of twice the last digit and the rest of the number is a multiple of 19
20: The number ends in 00, 20, 40, 60 or 80
21: The subtraction twice the last digit and the rest of the number is a multiple of 21
22: The number is a multiple of both 2 and 11
23: The sum of 7 times the last digit and the rest of the number is a multiple of 23
24: The number is a multiple of both 3 and 8
25: The number ends in 00, 25, 50 or 75
26: The number is a multiple of both 2 and 13
27: The subtracrion of 8 times the last digit and the rest of the number is a multiple of 27
28: The number is a multiple of both 4 and 7
29: The sum of 3 times the last digit and the rest of the number is a multiple of 29
30: The number is a multiple of both 3 and 10
31: The subtraction of 3 times the last digit and the rest of the number is a multiple of 31
32: The last 5 digits are a multiple of 32
33: The sum of 10 times the last digit and the rest of the number is a multiple of 33
34: The number is a multiple of both 2 and 17
35: The number is a multiple of both 5 and 7
36: The number is a multiple of both 4 and 9
37: The subtraction of 11 times the last digit and the rest of the number is a multiple of 37
38: The number is a multiple of both 2 and 19
39: The sum of 4 times the last digit and the rest of the number is a multiple of 39
40: The 3rd to last digit is even and the last 2 digits are 00, 40 or 80, or the 3rd to last digit is odd and the last 2 digits are 20 or 60
41: The subtraction of 4 times the last digit and the rest of the number is a multiple of 41
42: The number is a multiple of both 2 and 21
43: The sum of 13 times the last digit and the rest of the number is a multiple of 43
44: The number is a multiple of both 4 and 11
45: The number is a multiple of both 5 and 9
46: The number is a multiple of both 2 and 23
47: The subtraction of 14 times the last digit and the rest of the number is a multiple of 47
48: The number is a multiple of both 3 and 16
49: The sum of 5 times the last digit and the rest of the number is a multiple of 49
50: The number ends in 00 or 50
51: The subtraction of 5 times the last digit and the rest of the number is a multiple of 51
52: The number is a multiple of both 4 and 13
53: The sum of 16 times the last digit and the rest of the number is a multiple of 53
54: The number is a multiple of both 2 and 27
55: The number is a multiple of both 5 and 11
56: The number is a multiple of both 7 and 8
57: The subtraction of 17 times the last digit and the rest of the number is a multiple of 57
58: The number is a multiple of both 2 and 29
59: The sum of 6 times the last digit and the rest of the number is a multiple of 59
60: The number is a multiple of both 3 and 20
61: The subtraction of 6 times the last digit and the rest of the number is a multiple of 61
62: The number is a multiple of both 2 and 31
63: The sum of 19 times the last digit and the rest of the number is a multiple of 63
64: The last 6 digits are a multiple of 64
65: The number is a multiple of both 5 and 13
66: The number is a multiple of both 2 and 33
67: The subtraction of 20 times the last digit and the rest of the number is a multiple of 67
68: The number is a multiple of both 4 and 17
69: The sum of 7 times the last digit and the rest of the number is a multiple of 69
70: The number is a multiple of both 7 and 10
71: The subtraction of 7 times the last digit and the rest of the number is a multiple of 71
72: The number is a multiple of both 8 and 9
73: The sum of 22 times the last digit and the rest of the number is a multiple of 73
74: The number is a multiple of both 2 and 37
75: The number is a multiple of both 3 and 25
76: The number is a multiple of both 4 and 19
77: The subtraction of 23 times the last digit and the rest of the number is a multiple of 77
78: The number is a multiple of both 2 and 39
79: The sum of 8 times the last digit and the rest of the number is a multiple of 79
80: The 4th to last digit is even and the last 3 digits are a multiple of 80 or the 4th to last digit is odd and the last 3 digits are a multiple of 40 but not of 80
81: The subtraction of 8 times the last digit and the rest of the number is a multiple of 81
82: The number is a multiple of both 2 and 41
83: The sum of 25 times the last digit and the rest of the number is a multiple of 83
84: The number is a multiple of both 4 and 21
85: The number is a multiple of both 5 and 17
86: The number is a multiple of both 2 and 43
87: The subtraction of 26 times the last digit and the rest of the number is a multiple of 87
88: The number is a multiple of both 8 and 11
89: The sum of 9 times the last digit and the rest of the number is a multiple of 89
90: The number is a multiple of both 9 and 10
91: The subtraction of 9 times the last digit and the rest of the number is a multiple of 91
92: The number is a multiple of both 4 and 23
93: The sum of 28 times the last digit and the rest of the number is a multiple of 93
94: The number is a multiple of both 2 and 47
95: The number is a multiple of both 5 and 19
96: The number is a multiple of both 3 and 32
97: The subtraction of 29 times the last digit and the rest of the number is a multiple of 97
98: The number is a multiple of both 2 and 49
99: The sum of 10 times the last digit and the rest of the number is a multiple of 99
100: The number ends in 00
