36 of 100: Add Seven Subtract One
Logic
Level
1
\[\Large 1 \; \square \; 2 \; \square \; 3\; \square \; 4\; \square \; 5 \; \square \; 6 \; \square \; 7 \; \square \; 8 \; = 30\]
Six out of the seven "\(\square\)"s above contain addition signs, and the remaining "\(\square\)" contains a subtraction sign.
Where should the subtraction sign go to make the equation true?
Can you solve this puzzle without using guess-and-check at all? Strategy hint: what would the sum be if all the squares had addition signs?
by
Jason Dyer