Rivera

Steven Francis recently discovered Road Sign Math and has been searching for valid signs since, and found this one to send in for his first winner. Mr. Francis is a math teacher, so buckle your seat belts fans, it's going to get a little crazy.



Solutions
Mr. Francis submits this formula as the winner for the sign. It's well done, exercising a rare use of exponents.

$$3^{7-6} = \sqrt{9}$$

Mr. Francis also identified these formulas as straightforward ways to make the sign work.

$$7 - \sqrt{9} \div 3 = 6$$

$$7 + 6 \div 3 = 9$$

Now Mr. Francis decided to fire up the engines and have some fun. This formula doesn't seem to violate any rules, but even Mr. Francis was worried that it didn't match with the spirit of the game.

$$\int_3^6 {(x \cdot x) dx } = 7 \cdot 9$$

Reasoning this out…

$$\int_3^6 {(x \cdot x) dx } = \int_3^6 {x^2}dx = {1 \over 3}x^3\big|_3^6 = $$

$${1 \over 3 } (6^3 - 3^3) = {1 \over 3}(216 - 27) = {1 \over 3} (189) = 63 = 7 \cdot 9$$

Whew! Extra points if you are actually able to follow that!

This sign is found at the end of a service road that meets Passons Boulevard in Pico Rivera, California between the Sheriff's station and El Rancho high school where Mr. Francis works.