10.
A gallon = 4 quarts
4 quarts = 4 x 2 = 8 pints.
8 pints = 8 x 16 = 128 (ounces)
So, a gallon equals 128 ounces.
11.
Generally, 2 cups = 1 pint.
-> 4 cups = 2 pint = 1 quart
So, he should (probably) use the entire quart.
12.
Convert all the mixed numbers to fractions, mk.
14(7/9) + 6(5/9)
= 14+6(7/9+5/9) = 20(12/9) = 64/3.
13. 15(11/16) + 21(9/16) = 36(11/16+9/16) = 36(20/16) = 149/4
14. 7(1/2) + 5(1/2) = 12(1/2+1/2) = 13( = 13/1)
15. 17(3/4) - 4(1/4) = 17-4(3/4-1/4) = 13(1/2) = 27/2
16. 23(5/8) - 12(3/8) = 23-12(5/8-3/8) = 11(2/8) = 45/4
17. 27 - 6/8 = 216/8 - 6/8 = 210/8 = 55/2.
Please recheck and if you spot anything wrong tell me.