In this activity students construct multiplying slide rules scaled in Base-10 exponents and use them to calculate products and quotients. They will come to appreciate that super numbers (exponents, orders of magnitude and logarithms) play by different rules of arithmetic than ordinary numbers (numbers, powers of ten and antilogs). This is activity A2 in the "Far Out Math" educator's guide. Lessons in the guide include activities in which students measure,compare quantities as orders of magnitude, become familiar with scientific notation, and develop an understanding of exponents and logarithms using examples from NASA's GLAST mission. These are skills needed to understand the very large and very small quantities characteristic of astronomical observations. Note: In 2008, GLAST was renamed Fermi, for the physicist Enrico Fermi.