Question

Select the proper placement for parentheses to speed up the addition for the expression 4 + 6 + 5 

A. (5 + 6) + 4   B. (4 + 6) + 5   C. 4 + (6 + 5)   D. (5 + 4) + 6

Answer 1

the answer is B becuase 6+4=10 10+5=15

Answer 2

im guessing that by making 10 it will speed up the addition process so it should be
B since (6+4) = 10 then +5 =15