2.4 Addition and Subtraction on the Number Line
Unit Goals
- Students learn about the structure of a number line and use it to represent numbers within 100. They also relate addition and subtraction to length and represent the operations on the number line.
Section A Goals
- Represent whole numbers within 100 as lengths from 0 on a number line.
- Understand the structure of the number line.
Section B Goals
- Represent sums and differences on a number line.
Glossary Entries
- bar graphA way to show how many in each group or category using the length of rectangles.
- centimeter
A length unit in the metric measurement system. There are 100 centimeters in a meter.
- composeTo make a new unit from 10 of the next smallest unit. For example, compose a ten from 10 ones.
- dataInformation about the things or people in a group.
Example: If you have a box of colored pencils, then the lengths and colors of each of the pencils are data about the pencils in the box. - decomposeTo break a unit into 10 of the next smallest unit. For example, decompose a ten into 10 ones.
- foot
A length unit in the U.S. customary measurement system.
There are 12 inches in a foot.
- inch
A length unit in the U.S. customary measurement system.
There are 12 inches in a foot.
- line plotA way to show how many of each measurement using an x for each measurement.
- meter
A length unit in the metric measurement system.
There are 100 centimeters in a meter.
- number line
A diagram that represents numbers as lengths from 0 using equally spaced tick marks or points.
- picture graphA way to show how many in each group or category using pictures of the objects or symbols.