Lesson 1

The purpose of this lesson is for students to measure lengths that are fractions of an inch and relate these measurements to fractions on a number line.

In grade 2, students learned how to measure lengths to the nearest inch. They also learned how to represent fractions on the number line in the previous unit.

In this lesson, students start by measuring the length of objects using an inch ruler. As students find objects whose length is not a whole number of inches, they consider how to partition the inches to get a more precise measurement. Students then partition a ruler to show halves of an inch and use the ruler to measure lengths to the nearest half of an inch. The lesson synthesis introduces students to mixed numbers as numbers that combine whole numbers and fractions less than 1.

Students use the rulers they make in this lesson again in future lessons.

• Make copies and cut out the rulers from the blackline master (5 rulers per page). 

• Each student needs a ruler from the previous activity.

In the last unit, students learned how to represent fractions on diagrams and number lines. In what ways did you see students applying that experience here?