The two colons are for the answer

um, we can't do the x candies divided by y children because 1/4 children would be a problem

we can do this tho

you hae 2 and 1/2 cups of cupcake mix

each cupcake requires 1/4 cup of mix

how many cupcakes can you make?

one way is

cupsyouhave/cupsneededpercupcake=numberofcupcakes

2 and 1/2 divided by 1/4=number of cupcakes

remember that

first convert 2 and 1/2 to fraction

2 and 1/2=2+1/2=4/2+1/2=5/2

so

answer is 10