These highways signs are on the I-10 and US Hwy-60 entrance ramp at Baseline Road in Tempe, Arizona.

The highways signs say...

+---------------------+ +--------------+ | I-10 US-60 West | | Exit 154 | | Phoenix | | US-60 East | +---------------------+ | Mesa | | Globe | +--------------+the numbers are: 10 60 60 154 the math is: 60 - sqrt(154 - 10) = 60_{8}observe... 154 - 10 = 144 sqrt(144) = 12 60 - 12 = 48 base-8 is the "octal" number system 60_{8}= 6 * 8 + 0 * 1 = 48

**Creator:** Gerald Thurman
[gthurman@gmail.com]

**Created:** 19 June 2008

This work is licensed under a Creative Commons Attribution 3.0 United States License.