Question

Please help an 8-year-old! (it's not me)
Using only the digits 1, 4, 5, and 7, and one addition sign, and one subtraction sign, find a way to get the answer 19. ex: 57-1+4

Answer 1

it can only have an addition sign and a subtraction sign, no brackets or anything. No powers, bases or anything like that either.

Answer 2

basically something you can do on a non-programming, elementary-school calculator

Answer 3

can you use the digits more than once?

Answer 4

nope.

Answer 5

...Well, the closest I can get is 17+5-4=18
:/

Answer 6

XD that's how close I got.

Answer 7

We can use only + and - ?

Answer 8

yup, and you can only use each one time.

Answer 9

THinking..

Answer 10

I do so believe that this is the hardest third-grade question on openstudy...OTL

Answer 11

not possible

Answer 12

...ok... why?
This is a "three-star" problem on a 3rd grader's hw...it's not possible?

Answer 13

Does it have to use ALL the digits and signs?

Answer 14

yes. the image is a calculator with all the keys you have to use once checked.

Answer 15

can you please check to see if the whole question has be written correctly

Answer 16

it is.
here is the exact phrasing:
Below each calculator, write a number sentence to give the answer shown. The symbols and digits to use are checked on each calculator.
the answer is 19. The digits and symbols are 1, 4, 5, 7, -, + and =.

Answer 17

Wait, if that's the exact question, then does it say in the -directions- to use everything once?

If so, then I have to agree with UnkleRhaukus. I can only get as far as 18 with these numbers.

Answer 18

lol, same here.. i dont knw where to add 1. keep on gettinh 18.

Answer 19

it does't explicitly say, but all the other questions like that on the same sheet only use each digit once.

Answer 20

Ahhhh. This is making my brain hurt.

Either it's a type of trick question where you do use them more than once, like:
17 + 5 - 4 + 1 = 19
Or a typo.

I'm sorry, I just can't figure this one out. ):

Answer 21

might be a mis-print in the book?

Answer 22

it's not a book...but perhaps.