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.
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 second number.
This is a positive number - but we are subtracting so the blue arrow moves to the left starting from the end of the red arrow.
d. DIFFERENCE: What is the difference?
• Click on "Show Difference " to see it on the number line.
e. EQUATION: Write down the equation for the subtraction.
• Click on Show Equation to check your answer.
•Click on Reset to start over.