    Number Line
Unit Background

Teacher Portal

# Background

Tools are utilized every day by people to help them accomplish tasks and solve problems. This Number Line: Addition Unit will familiarize you and your students with specific tools that help solve addition equations. The tools that your students will use include a 123 Robot, a number line, and manipulatives. Students will also learn how to move their 123 Robot on a number line effectively to solve equations.

## Number Line

A number line is a line of numbers marked at certain intervals or equal spaces with numbers placed in a particular order. The numbers ascend moving positively from zero and descend moving negatively from zero. It is a useful tool for adding and subtracting numbers. Moreover, the number line helps students visualize numbers while solving problems. The number line also helps represent a one-to-one correspondence. One-to-one correspondence is the ability to match one object to one (corresponding) number or object. Students will know one movement of the 123 Robot on the number line is equal to the number one being added in an equation.

## Manipulatives

Manipulatives are physical objects used in hands-on learning experiences to represent a concept. In this unit, crayons are the suggested manipulatives. Manipulatives are helpful to students when solving math equations because the students can visualize the numbers they are adding together. The manipulatives also support students in relating counting to addition and subtraction. Students will be asked to count the manipulatives in order to equal the same number as the sum of the addition problem during the activities. This is a great way for students to check their work to make sure the manipulatives match the answer to the equation which students get to do in Lab 2 Play Part 1 and Play Part 2.

## One-to-One Correspondence

It is usually explained as the ability to match one object to one (corresponding) number or object.

• Example: 1 button press on the 123 Robot = 1 movement