If milk cost $0.58 per gallon, how much would 3 1/2 cost? !

3 1/2 is the same thing as 3.5 (I find it's easier to work with decimals rather than with fractions)!

You need to do a cross product in order to find your

1 gallon of milk = 0.58$

3.5 gallons of milk = X$

(0.58 × 3.5) ÷ 1 = X$

2.03 ÷ 1 = X$

2.03 = X$

Your answer is : 3 1/2 gallons of milk would cost $2.03

There you go! I really hope this helped, if there's anything just let me know! :)