The number 8 is the smallest positive integer that is not a multiple of 3.

Here are some examples of numbers that are multiples of 3 but not 8:

* 3
* 6
* 9
* 12
* 15
* 18
* 21
* 24
* 27
* 30
* 33
* 36
* 39
* 42
* 45
* 48
* 51
* 54
* 57
* 60
* 63
* 66
* 70
* 73
* 76
* 79
* 82
* 85
* 88
* 91
* 94
* 97
* 100
* 103
* 106
* 109
* 112
* 115
* 118
* 121
* 124
* 127
* 130
* 133
* 136
* 139
* 142
* 145
* 14