For example:
Decimal to binary:
Divide by 2 until the result is 1.
Writing the remainder and the last 1 in reverse order from bottom to top is the result.
Such as 302
302/2 = 15 1 greater than 0.
15 1/2 = 75 1
75/2 = 37 remainder 1
37/2 = 18 1
18/2 = 9+0
9/2 = 4 remainder 1
4/2 = 2+0
2/2 = 1+0
So the binary number is10010110.
Can be abbreviated as "divide by two, take the remainder"
The same is true of other situations.