1 2 3 4 5 6 7 8 9 = 100

This equation is incomplete: 1 2 3 4 5 6 7 8 9 = 100

One way to make it accurate is by adding seven plus and minus signs, like so.

1 + 2 + 3 – 4 + 5 + 6 + 78 + 9 = 100

How can you do it using only 3 plus or minus signs?

123 – 45 – 67 + 89 = 100

Posted in Brain Teasers

42 Comments on "1 2 3 4 5 6 7 8 9 = 100"

Pennywise says
February 1, 2021 @ 04:26

123 – 45 – 67 + 89 = 100

MUHAHAHAAAAA

laray kiene says
February 3, 2021 @ 08:03

1+2+3+4+5+6+7+8×9 does not equal 100 it equals 324. search it up! use ur calculator. but thank you for the others that have given other calculations you really helped me with my maths work!

Deepak murmu says
February 3, 2021 @ 11:06

123+45+67+89=324 I use my calculator

Ruby says
May 20, 2021 @ 13:47

1+2+3+4+5+6+7+(8*9)

i.m.verystupid says
July 29, 2021 @ 01:55

the correct answer is -1+2+3+4 x 5 x 6 -7-8-9

Pretty smart guy says
October 16, 2021 @ 17:33

8
∑3n-1 = 100
n = 1

Louis says
October 27, 2021 @ 02:46

1+2+3+4+5+6+7+8×9=100

100?!

Tim says
February 15, 2022 @ 17:42

I have over 600 ways of doing this. I have been teaching Maths for almost 40 years and have set this challenge to my pupils every year. Some of the solutions are wonderfully arcane and others are astonishingly simple.

Michelle says
January 5, 2023 @ 21:08

That is not clever I want 1,2,3,4,5,6 and 7

Hiiiiiiii says
January 5, 2023 @ 21:11

You are sooooooooo smart smarter than my sister!!

reza says
June 22, 2023 @ 07:59

[[123, ‘+’, 45, ‘-‘, 67, ‘+’, 8, ‘-‘, 9], [123, ‘+’, 4, ‘-‘, 5, ‘+’, 67, ‘-‘, 89], [123, ‘-‘, 45, ‘-‘, 67, ‘+’, 89], [123, ‘-‘, 4, ‘-‘, 5, ‘-‘, 6, ‘-‘, 7, ‘+’, 8, ‘-‘, 9], [12, ‘+’, 3, ‘+’, 4, ‘+’, 5, ‘-‘, 6, ‘-‘, 7, ‘+’, 89], [12, ‘+’, 3, ‘-‘, 4, ‘+’, 5, ‘+’, 67, ‘+’, 8, ‘+’, 9], [12, ‘-‘, 3, ‘-‘, 4, ‘+’, 5, ‘-‘, 6, ‘+’, 7, ‘+’, 89], [1, ‘+’, 23, ‘-‘, 4, ‘+’, 56, ‘+’, 7, ‘+’, 8, ‘+’, 9], [1, ‘+’, 23, ‘-‘, 4, ‘+’, 5, ‘+’, 6, ‘+’, 78, ‘-‘, 9], [1, ‘+’, 2, ‘+’, 34, ‘-‘, 5, ‘+’, 67, ‘-‘, 8, ‘+’, 9], [1, ‘+’, 2, ‘+’, 3, ‘-‘, 4, ‘+’, 5, ‘+’, 6, ‘+’, 78, ‘+’, 9]]

1 2 3