Welcome to a lesson on how to subtract whole
number using the number line.
Whole numbers are the numbers 0, 1, 2, 3,
4, 5 and so on.
To subtract means to remove or take away.
We can write subtraction problems horizontally
or vertically.
Both are read A minus B equals C. Where A,
the quantity we begin with is called the minuend.
B, the quantity we subtract or remove is called
the subtrahend.
And C, the result of the subtraction is called
the difference.
And now let's subtract whole numbers using
the number line.
We will first model 9 minus 7 using this number
line tool.
We first model 9 by dragging the bottom point
9 units to the right of 0 to positive 9 on
the number line.
Now because we are subtracting 7 or removing
7 from 9, move the top point left 7 units.
So 1, 2, 3, 4, 5, 6, 7 units back to the left.
We are now at positive 2 on the number line,
which shows 9 minus 7 equals 2.
Now we will model 8 minus 2 using the number
line.
We begin by modeling 8 on the number line,
by moving the bottom point right 8 from 0
to positive 8 on the number line.
And now because we are subtracting 2, we move
the top point left 2 unit.
We are now at positive 6 on the number line.
8 minus 2 equals 6.
I hope you found this helpful.
