# Can you correct the equation by moving one matchstick?

#1

The puzzler regarding moving a matchstick is bO-O=O-O…gus. 22/7 exceeds the value of pi by about 0.04% as proven by my know-it-all son the mechanical engineer. After suffering our catcalls, he quickly brought up an excel spreadsheet which has a “pi” function and then displayed 22/7 in an adjacent cell.
Divide the two cells to most clearly display the deviation.
There is another answer which his genius father…me… came up with: take the 1 matchstick and put it diagonally through the equal sign to give 22/7 does not equal 2.
Hurray…the college tuition wasn’t wasted.

#2

I agree; for their solution to be valid, you’d have to change the equals sign to the approximate equals sign. They did say it must be an equation and not an inequality, which IMHO also rules out approximations.

#3

Ok, I think I have a solution that – while bogus – maybe isn’t as bogus as the brother’s … lol …

## X X I I I = I I

V I I

Take the third “I” in the numerator, and use it form (an admittedly slightly askew) “V” from the first “I” in the denominator.

## X X I I = I I

V V I

In decimal, 22/11 = 2, right?

Me, I’m just happy the folks at NASA don’t use 22/7 for Pi!! Otherwise rocket trips to Mars might end up going to Saturn instead.

#4

I see nothing bogus in your solution. Good job!

#5

As long as we’re playing by horseshoe rules, if you move one of the toothpicks forming the “V” in the denominator and slide it over to turn the “V” into and “X”, then you have 23/12 = 2. That’s just about as accurate as 22/7=pi.

#6

George: Changing the angle is moving a stick, so you moved 2. Also they said one can’t leave a single diagonal line as that doesn’t mean anything in Roman numbers.
And VVI is not valid.

Tom \$ Ray: Pi is Greek letter, not a Roman numeral. Another answer is to move a I from the numerator and place it next to the II on the right of the equal sign. so:
22/7=3. Roman numeral calculators on-line gives rounded integer answers. Still, even this is not correct. The Romans had a complex system for non-integers based on 12ths. 22/7 > 3.08333… So 22/7 would round to 3 1/12. I don’t know how to write it.

I think the closest answer is what straight6 suggested. Still not 2…