3.1:10.261 how to show my work

First, convert the decimals into improper fractions. The fractions are:

31/10 and 10261/1000. To divide the fractions, change division into multiplication after flipping the numerator and the denominator of the second fraction. This comes out to be 31/10 * (times) 1000/10261.

31*1000 is 31,000 and 10*10261 is 102,610. This equals the fraction: 31,000/102,610. Simplify this.