### Brain Teasers

# 1 2 3 4 5 6 7 8 9 = 100

Can you place + and - signs between the following numerals to make the equation true? You can only use a total of 3 symbols and you cannot rearrange the numerals.

1 2 3 4 5 6 7 8 9 = 100

1 2 3 4 5 6 7 8 9 = 100

### Hint

You will use - - +, in that order.### Answer

123 - 45 - 67 + 89 = 100Hide Hint Show Hint Hide Answer Show Answer

## What Next?

**Solve a Similar Brain Teaser...**

Or, get a random brain teaser.

If you become a registered user you can vote on this brain teaser, keep track of

which ones you have seen, and even make your own.

## Comments

FUN!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

That was actually pretty tricky.

the hint made it a lot easier, but still pretty tricky. fun though

I had a different way of doing it. I thought it was a trick and you could change the + to an x by turning it on it's side and do:

1+2+3+4+5x6-7+8+9=100

1+2+3+4+5x6-7+8+9=100

I recently had a challenge in this regard... come up with as many solutions as possible, except you can use x , / and brackets as well. I got 21. Anyway, this teaser is a really interesting variation! fun!

Actually, Shawn, you couldn't do that because it says you can only use 3 symbols.

shawn is my brother, i wish

why are you trying so hard to make me think ?!!

i will not do it !!!

i will not do it !!!

Shawneyheyhey123 is wrong.

you can only use three symbols!

you can only use three symbols!

got it with the hint

Very clever!

Got it in less than thirty seconds without the hint.

Since only three symbols could be use either two, three or four of the numbers needed to be relatively close in value. There wasn't any way to make two 4-digit, or a 4-digit and 3-digit number, or two 3-digit numbers that were close, so it had to be one 3-digit number and three 2-digit numbers. The 3-digit number had to be 123, which left 45, 67 & 89. The 23 from 123 had to go with 89, so 45 and 67 had to be the negatives and 123 and 89 the positives. No trial and error, just wrote out the solution.

Piece-o-cake!

Since only three symbols could be use either two, three or four of the numbers needed to be relatively close in value. There wasn't any way to make two 4-digit, or a 4-digit and 3-digit number, or two 3-digit numbers that were close, so it had to be one 3-digit number and three 2-digit numbers. The 3-digit number had to be 123, which left 45, 67 & 89. The 23 from 123 had to go with 89, so 45 and 67 had to be the negatives and 123 and 89 the positives. No trial and error, just wrote out the solution.

Piece-o-cake!

## Follow Braingle!