Math Moment –
Automotive Technologies
HS.N-Q.A.1 Use units as a way to understand problems and to guide the solution of multi-step problems; choose and interpret units consistently in formulas; choose and interpret the scale and the origin in graphs and data displays.
Property of Pima County JTED 2014

You will need:




Conversion sheet
Calculator
Note-taker
Worksheet

Automotive Technologies
Unit Conversion
AKA Dimensional Analysis

Bellwork

Think about times you have needed to convert from one unit to another.

List at least 1 on your note-taker.

Share with your partner.

Possible Answers

Converting money
◦ Dollars to quarters

Convert time
◦ Hours to minutes

Convert distance
◦ Feet to yards

Math Check
The math skill you will need to know to be successful today is multiplying fractions.
Remember: numerator denominator
1.
1.
2
3

9
16

6

3
8
=

Terminology

Conversion factor – when two quantities are equal, but have different units.
◦ Example: 1 minute = 60 seconds

Vocabulary Square
2
1
Fill this in during the lesson

Benefits for You



Consistent problem solving approach
Simplified computation
Same strategy is used in math, chemistry and physics

Steps
2.
3.
4.
1.
5.
Write down what you are given as a fraction
Find the conversion factor or factors
Set up the equation
Cancel units – make sure the remaining units are what you want
Do the math

Learn the steps

Take 60 seconds and learn the 5 steps
1.
2.
3.
4.
5.
Write given as fraction
Find the conversion factors
Set up the equation
Cancel units
Do the math

Check the Steps
Number the steps from 1-5 to put them in the correct order.
2.
Find the conversion factors
3.
Set-up the equation
5.
Do the math
4.
Cancel units
1.
Write given as a fraction

Example 1
Convert $5 to quarters
Step 1: Write what you are given as a fraction
$5
1

Step 2: Find the conversion factor or factors
$1 = 4 quarters


Step 3: Set up the equation
$5
•
1
4 quarters

$1


Step 4: Cancel the units
$5
•
1
4 quarters

$1


Step 5 Do the math
$5
•
1
4 quarters
= 20 quarters
$1

You try!

Convert 38.42 cm to inches
1. Write given as fraction
2. Find the conversion factors
3. Set-up the equation
4. Cancel the units
5. Do the math

You try! Answer

Convert 38.42 cm to inches
38.42
cm

1
1 in
2.54
cm

15.13
in
Step 1 Write given as fraction
Step 2 Find conversion factor
Step 3 Set-up equation
Step 4 Cancel the units
Step 5 Do the math

Example 2

Convert 570 mm to cm

Example 3 – multi-step

Convert 3 days to minutes

Example 4 – Multi-steps

Convert 65 miles per hour to feet per minute
◦ Hint: per means division

Example 5
A mechanic is working on two engines. One is a 5.4L engine while the other is a 350 cubic inch engine. Which engine is bigger?

Scenario – Who is faster?

Mr. Yandell is running at 5 miles per hour.

Mr. Ramsey is riding his bike at 12 feet per second.

Who is faster?

Who is faster Answer

The most common unit of speed is miles per hour so I will convert Mr.
Ramsey
12 ft sec miles hour

Conversion Factors




1 foot = 12 inches
1 mile = 5280 feet
1 minute = 60 seconds
1 hour = 60 minutes

Set-up

Does the order of the terms matter?
12 ft
1sec
12 ft
1sec


60sec
1min

60 min
1 hr
1 mile
5280 ft

60sec
1min


1 mile
5280 ft
60 min
1 hr
12 ft 60 min 1 mile

60sec
 
1sec 1 hr 5280 ft
Can you write another ordering?
1min

Other Orderings
60sec

1min
12 ft
1sec

1 mile
5280 ft

60 min
1 hr

Why??

The Commutative Property of
Multiplication (AzCCRS 3.OA.B.5)


Winner!!

Mr. Yandell 5 mph

Mr. Ramsey 8.18 mph
Mr. Ramsey is the winner!

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In 12 words or less, summarize the most important aspects from today's lesson.
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