math

posted by on .

For example,

1 + 2 + 3 + – 4 + 5 + 6 + 78 + 9 = 100

Can you obtain a total of 100 using fewer plus or minus signs than in the given example?

• math - ,

You could get rid of the + in front of -4. It would not change a thing.

• math - ,

1--- 1 + 2 + 3 + 4 + 5 + 6 + 7 + (8X9) = 100
2--- -(1X2) - 3 - 4 - 5 + (6x7) + (8X9) = 100
3--- 1 + (2X3) + (4x5) - 6 + 7 + (8x9) = 100
4--- (1 + 2 - 3 - 4)x(5 - 6 - 7 - 8 - 9) = 100
5--- (1 +(2x3) + 4 + 5 + 67 + 8 + 9 = 100
6--- (1X2) + 34 + 56 + 7 - 8 + 9 = 100
7--- 12+ 3 - 4 + 5 + 67 + 8 + 9 = 100
8--- 123- 4 - 5 - 6 - 7 + 8 - 9 = 100
9--- 123 + 4 - 3 + 67 - 8 - 9 = 100
10--- 123 + 45 - 67 + 8 - 9 = 100
11--- 123 - 45 - 67 + 89 = 100 WOW

You might also be surprised to see that it can be done in the reverse also.

1-- 98 - 76 + 54 + 3 + 21 = 100
2-- 9 - 8 + 76 + 54 - 32 + 1 = 100
3-- 9 - 8 + 7 + 65 - 4 + 32 - 1 = 100
4-- 9 - 8 + 76 - 5 + 4 + 3 + 21 = 100
5-- 98 - 7 - 6 - 5 - 4 + 3 + 21 = 100
6-- 9 + 8 + 76 + 5 + 4 - 3 + 2 - 1 = 100
7-- 9 + 8 + 76 + 5 - 4 + 3 + 2 + 1 = 100
8-- 98 + 7 + 6 - 5 - 4 - 3 + 2 - 1 = 100
9-- 98 + 7 - 6 + 5 - 4 - 3 + 2 + 1 = 100
10-- 98 + 7 - 6 + 5 - 4 + 3 - 2 - 1 = 100 To name a few.

• math - ,

No it's the other way around Get it?