F.U.N. stands for Fluency and Understanding Numbers. This set of 240 cards for grades K-1 allows you to add cards to your F.U.N.™ Empty Number Line System (sold separately). Demonstrates that the magnitude of the numbers increases as a student is 'counting up' and decreases when 'counting down'. Additionally, decomposing numbers into pairs can be displayed, and comparing one digit or two digit numbers can be modeled. The number line can be used to quickly indentify '10 more' or '10 less', as well as many other concepts. Great for math coaches and remedial teachers and others that teach across grade levels. Set includes 30 write-on / wipe-off cards for versatility.