re color coded to make it easy for students to recognize odd and even numbers. Each set of student number lines includes 30 number lines that measure 22" x 1.5" each. They also feature a write-on/wipe-away surface to make it easy for students to use over and over again! Student number lines are the perfect hands-on tool for reinforcing mathematical concepts such as counting, identifying number patterns, partitioning numbers, comparing numbers, and building number sense.