Texas Essential Knowledge and Skills (TEKS):
1.7.a
use measuring tools to measure the length of objects to reinforce the continuous nature of
linear measurement;
Texas Essential Knowledge and Skills (TEKS):
1.7.b
illustrate that the length of an object is the number of same-size units of length that, when
laid end-to-end with no gaps or overlaps, reach from one end of the object to the other;
Texas Essential Knowledge and Skills (TEKS):
1.7.c
measure the same object/distance with units of two different lengths and describe how
and why the measurements differ;
Texas Essential Knowledge and Skills (TEKS):
1.7.d
describe a length to the nearest whole unit using a number and a unit; and
Florida - Benchmarks for Excellent Student Thinking:
MA.1.1.1
Estimate the length of an object to the nearest inch. Measure the length of an object to the nearest inch or centimeter.
Florida - Benchmarks for Excellent Student Thinking:
MA.1.1.2
Compare and order the length of up to three objects using direct and indirect comparison.
1st Grade Math - Length Lesson
Measure Length
Length
Length is how long something is. We measure length with units. A unit is a small piece that is always the same size, like a cube.
To measure, units are lined up from one end to the other end. There are no gaps and no overlaps. We tell a length to the nearest whole unit. We use a number and a unit, like 5 cubes. If the object ends more than halfway across a cube, count that cube. If it ends less than halfway across a cube, do not count that cube.
Example:
The ribbon starts at the left end of cube 1. Count the cubes under the ribbon: 1, 2, 3, 4.
The ribbon ends at the end of cube 4. It is four cubes long. Say the number and the unit.
4 cubes
Example:
The pencil covers five whole cubes. It ends inside cube 6.
The pencil covers more than half of cube 6. So we count cube 6.
The pencil is about six cubes long.
about 6 cubes
Example:
The crayon covers three whole cubes. It ends inside cube 4.
The crayon covers less than half of cube 4. So we do not count cube 4.