The fundamental theorem of arithmetic in practice: Prime numbers are the basic building blocks of numbers, Cryptographic protocols are based on Prime Numbers THE APP: At left: two abacus (two numbers stacked) - Place Value and Tokens. At right two circles with the prime factors. (two circles with prime numbers stacked) At right edge: all the prime numbers available to the app. To create a number: Tap on the cells at left. The app shows the number To add: Drag the tokens from one abacus to t