Multiply both the dividend and divisor by 10 (move their decimal points
each one place to the right) to get a new division problem with the same
quotient:
1217.7 ÷ 12.3
The divisor is still a decimal, so multiply by 10 (move the decimal points) again:
12,177 ÷ 123
This'll have the same quotient as 121.77 ÷ 1.23.
By working out the division, we get 12,177 ÷ 123 = 99. Sounds like a bargain.