This poster is 18 inches horizontally by 12 inches vertically. The background is an old fashioned green chalkboard with all the fixings (chalk, erasers, and a red apple to boot). On the chalkboard there are 662 digits of Pi and with each digit the font size decreases by .5. The writing looks like chalkboard writing and is a great addition to the math classroom dÃ©cor. You can also download a printable file but that is found in a different post.