The Number Line

a. SCALE: Set the scale of the number line that is:

• Type in a number >=1 and <=500.

• Then click on the **Set Scale** button.

**Remember:** arrow for first number starts from 0, arrow for second number starts from end of first arrow.

• Now click on Ready for First Number.

b. FIRST NUMBER: Click and drag the point on the red slider to the value of the first number you want to add.

This is a positive number **and** it is the first number so the red arrow moves to the right starting from **0** (zero).

• Now click on Ready for Second Number.

c. Second Number: Click and drag the point on the blue slider to the value of the number you want to add.

This is a positive number **and** addition so the blue arrow moves to the right starting from the end of the red arrow.

d. SUM: What is the sum?

• Click on "Show Sum" to see sum on the number line.

e. EQUATION: Write down the equation for the addition.

• Click on Show Equation to check your answer.

• Click on **Reset** to start over.

LFS with idea for number line by Megan Yanes and for pseudo-slider by Zen Biker Maniac - Created with GeoGebra