# Make the Number 100 Puzzle - Solution

## The Puzzle:

Using the numerals 1,7,7,7 and 7 (a "1" and four "7"s) create the number 100.

As well as the five numerals you can use the usual mathematical operations +, −, ×, ÷ and brackets ().

For example: (7+1) × (7+7) = 112 would be a good attempt, but not right, because it is not 100.

## Our Solution:

We know of these solutions:

177-77 = 100
(7+7) × (7+(1 ÷ 7)) = 100

77/.77 × 1 by Jim Schuller

And all of these are by Robert Veith:

77/.1/7.7
77/7.7/.1
(77 - 7)/7/.1
(77 - 7)/.7/1
(77 - 7)/1/.7
(77 - 7)/.1/7
(7.7 - .7)/.7/.1
.7/(.77 - .7)/.1
(7.7 - .7)/.1/.7
1(7)/(.77 - .7)
7/(.77 - .7)/1
7/.7*7*(1/.7)
1/(.77/77)
7/.7*7/.7*1
1/(.7/7*.7/7)
1/(.7/7)/(.7/7)
(71 - 7/7)/.7
(17 - 7)*(7/.7)
7/(.17 - .7/7)
1/(.7/(77 - 7))
1/((.77 - .7)/7)
(7/7)*7/.1/.7
(7 + 7 - 7)/(.7*.1)
(17 - 7)/(.7/7)
(7/7)*7/.7/.1
1*7*7/(.7*.7)
1/((.7*.7)/(7*7))
(7/.7 + .7)/.1 - 7
7.7/.1/.77
(7/.1 + 7)/.77
(7/.1 + 7 - 7)/.7
(7/.7 + 7 - 7)/.1
7/(7.7 - 7)/.1
7/.1/(7.7 - 7)
7/(7(.71 - .7))
(7/7)/(.71 - .7)
7/(.71 - .7)/7
(7 + 7)/(.7 + .7)/.1
(7 + 7)/.1/(.7 + .7)
7/(.1 + 7 - 7)/.7
1(7/.7)/(.7/7)
(7 + 7 - 7)/.7/.1
7/.7/.1 + 7 - 7
7/.1/.7 + 7 - 7
7/.7/(.1 + 7 - 7)
7/.1/(.7 + 7 - 7)
7/(.7 + 7 - 7)/.1
(7 + 7 - 7)/.1/.7
1*(77 - 7)/.7
(7/.7 - .7)/.1 + 7
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