The inch ruler is a great model for identifying and using fractions to add and subtract. But many of the rulers we have in elementary school are not very practical for use by 4th graders – sixteen is just too many parts for students just beginning to understand fractions.
So here are problems involving identifying, adding, and subtracting fractions and mixed numbers on rulers divided into fourths and eighths. Introductory pages have images of rulers sized for Fraction Towers so students can easily identify the number represented by each tick.
At each step, addition and subtraction are modeled as counting on or back on the ruler, and also done numerically. All problems involve like denominators only. Problems requiring regrouping of a unit into fractional parts are introduced about midway through these pages.
These activities assume some familiarity with addition and subtraction of fractions, and simplifying. The package includes a legal-sized page each of 1-foot paper rulers marked in fourths, and another page in eighths. After laminating, these rulers will make it much easier for students to identify eighths and the equivalent fractions in fourths.
Common Core Standards:
4.NF.3c: “Add and subtract mixed numbers with like denominators…”
4.NF.3d: “Solve word problems involving addition and subtraction of fractions...by using visual fraction models and equations to represent the problem.”
Subjects: Math, Fractions, Measurement, Word Problems
Level: Grades 3-4
Duration: 22 pages of student work, many problems, 2-5 days
Answer Key: Yes
A Smartboard 10 file is also included. Click on the zip file icon, and you can open the PDF and Smartboard files separately.