Learning Advantage F.U.N. Empty Number line, Cards Only, Grade 4-5This set of 511 cards for grades 4 5 allows you to add cards to your F. U. N. Empty Number Line System (sold separately). Teachers students can extend previous work and use the number line for increasingly complex whole number calculations and to compare multi digit whole numbers. It can be used to focus on additional grade level targets, including comparing fractions, multiplying fractions by whole numbers, adding and subtracting fractions, and