~ 5.11 ~
Dividing Rational Numbers
Learning Targets
I can divide rational numbers.
Notes
Any division problem is actually a multiplication problem:
Because we know how to multiply signed numbers, that means we know how to divide them.
The sign of a positive number divided by a negative number is always negative.
The sign of a negative number divided by a positive number is always negative.
The sign of a negative number divided by a negative number is always positive.
Activities
11.2 Multiplication and Division
Find the missing values in the equations
-3 • 4 = ?
-3 • ? = 12
3 • ? = 12
? • - 4 = 12
? • 4 = -12
Rewrite the unknown factor problems as division problems.
Complete the sentences. Be prepared to explain your reasoning.
The sign of a positive number divided by a positive number is always:
The sign of a positive number divided by a negative number is always:
The sign of a negative number divided by a positive number is always:
The sign of a negative number divided by a negative number is always:
Han and Clare walk towards each other at a constant rate, meet up, and then continue past each other in opposite directions. We will call the position where they meet up 0 feet and the time when they meet up 0 seconds.
Han's velocity is 4 feet per second.
Clare's velocity is -5 feet per second.
Where is each person 10 seconds before they meet up?
When is each person at the position -10 feet from the meeting place?
11.3 Drilling Down
What do you remember about proportional relationships?
We can write equations about proportional relationships and they look like y = kx.
A graph representing a proportional relationship is a line through (0,0) and (1, k).
A water well drilling rig has dug to a height of -60 feet after one full day of continuous use.
Assuming the rig drilled at a constant rate, what was the height of the drill after 15 hours?
If the rig has been running constantly and is currently at a height of -147.5 feet, for how long has the rig been running?
Use the coordinate grid to show the drill’s progress, in your workbook or Geogebra: https://www.geogebra.org/m/rp3yp8tc
At this rate, how many hours will it take until the drill reaches -250 feet?
Summary
Assignment
Check Google Classroom!