Inspired by this post, here there is my attempt at a matches' puzzle. The expression 1 = 850 - 9 - 6 is obviously wrong: move exactly three matches to obtain a correct expression.
- This is not a digital display, so digits may be built differently;
- no roman numerals are allowed;
- operators $ \ne , \gt , \lt $ are not allowed;
- other operators like parentheses (two matches at a much larger angle than $ \lt \gt $ ) and root (three matches) are allowed;
- there is no space for inserting digits or operators, except at the far left and far right.