Patent ID: 7415772

Claim:
A set of rulers for teaching students to read measurements, said set comprising: a) a first ruler having a first group of incremental division lines for a first group of measured lengths, each of said lines of said first group having a first length extending from a proximal end to a distal end and being of a first color; b) a second ruler having said first group of incremental division lines of said first length and said first color and a second group of incremental division lines for a second group of measured lengths, each of said lines of said second group having a second length and a second color, said second group of lines having a proximal end beginning at and extending from a distal end of said lines of said first group when said second group of measured lengths correspond to said first group of measured lengths; c) a third ruler having i) said first group of incremental division lines of said first length and said first color, ii) said second group of incremental division lines of said second length and said second color and, iii) a third group of incremental division lines for a third group of measured lengths, each of said lines of said third group having a third length and a third color, said third group of lines having a proximal end beginning at and extending from a distal end of said lines of said second group when said third group of measured lengths correspond to said first group and said second group of measured lengths.