307
There's an infinite list of pairs of numbers that can do that. If you only want whole numbers, then you're stuck with only these: 1 x 18, 2 x 9, and 3 x 6
-1
1,2,3,6,9 & 18 !
You can multiply the number 18 by different numbers that are relatively prime, for example by different prime numbers.
307
There's an infinite list of pairs of numbers that can do that. If you only want whole numbers, then you're stuck with only these: 1 x 18, 2 x 9, and 3 x 6
Multiply 18 by successive counting numbers.
Multiply 11 by 18 and multiply that total by successive counting numbers.
Presumably, the theory is that it's easier to multiply by small numbers than larger ones. If there's a number that you need multiplied by 18, multiply it by 3, then multiply that total by 3, then multiply that total by 2.
-18 and -18
-1
How about: 3 times -6 = -18 as one example
1 and 108 2 and 54 3 and 36 4 and 27 6 and 18 9 and 12 (There are infinitely more numbers [that are not whole numbers] that you can multiply together to get the same answer)
15
1,2,3,6,9 & 18 !
You can multiply the number 18 by different numbers that are relatively prime, for example by different prime numbers.