SAT PREP - Problem 1

Question

Harry and Terry are each told to calculate . Harry gets the correct answer. Terry ignores the parentheses and calculates . If Harry's answer is  and Terry's answer is , what is ?

Answer 1

8-(2+5) = 8-7=1

8-2+5 = same if you follow PEMDAS, with Addition 1st, Subtract last

so difference = 0

but if you ignore PEMDAS and do an English grammar left to rigtht 3rd grad teacher directed exercise then

8-2+5 = 6+5 = 11

then difference = 1-11= -10

odds are -10 is the answer you want, regardless how wrong or how demanding your 3rd grade English teacher

PEMDAS = Please Excuse My Dear Aunt Sally. If you watch 3rd rock from the sun, better idea to listen to Sally than your 3rd grade grammar teacher.

P for Parentheses

E for Exponents

M for Multiply

D for Divide

A for Addition

S for Subtract

that's the arithmetic order of operations.

with no parentheses 8-2+5 2+5 is done 1st, then 8-7=1

not 8-2=6 and 6+5=11

so H-T = 1-1 = 0, not 1-11 =-10

if you miss some SAT questions it may not be your fault, it could be SAT grades their tests incorrectly

Answer 2

Harry answers correctly, meaning he follows the order of operations stating that the operation within the parentheses should be first. Terry ignores the parentheses and calculates from left to right.

Harry's Method: Terry's Method:

8 - (2+5) 8 - 2 + 5

8 - (7) 6 + 5

1 11

The problem asks what is Harry's answer minus Terry's answer.

1 - 11 = -10

Answer 3

We have  and . Clearly  , so our answer is .