conversions.notebook
October 22, 2014
Unit Conversion Pre­assessment
Problem of the Day
1) 3 mi. = ____ km
1 in = 2.54 cm
1. 565 ­ (32 2) 23
Choose the solution that makes the following equation true.
1 ft = 0.3 m
2) 4.5 in = ____cm
1 mi = 1.6 km
1 lb = 0.45 kg
3) 12m = ____ ft
1 gal = 3.79 l (liters)
2. 14 784
Math is awesome!!
3. Write an algebraic expression:
16 + 3x = 40
a. 2 c. 8
b. 5 d. 21
I eat little birds
for breakfast
1) 4.8 km
23 less than the difference of 87 and a number, h.
2) 11.43 cm
3) 3.6 ft
Mildred Livingstone
7th Grade Math
Jay M. Robinson Middle School
Oct 25­2:51 PM
Sep 10­12:50 PM
Oct 25­12:20 PM
Oct 25­12:20 PM
Unit Analysis
Compare different systems of measurement and use rate reasoning to devise a method to convert measurement units.
Oct 25­12:21 PM
Oct 19­3:01 PM
1
conversions.notebook
October 22, 2014
What are the two systems of measurement that you are familiar with?
Where are they used?
Customary or Standard
Metric
http://www.brainpop.com/science/scientificinquiry/metricunits/preview.weml
http://www.brainpop.com/math/numbersandoperations/customaryunits/preview.weml
Oct 19­3:54 PM
Oct 19­3:12 PM
Have you ever had problems deciding when to multiply or divide when converting? Proportions solve this problem!!!!
For example, there are 12 inches in one foot. How many inches are there in 4 feet?
Set up your proportion:
Oct 19­3:08 PM
There are 3 feet in one yard. How many yards is 12 ft.?
Oct 24­2:46 PM
Try this problem:
Kylie needed 6 yards of fabric to make her Halloween costume. How many feet of fabric does Kylie need?
Set up your ratio:
1 y
Answer
Why in the world would one need to know how to convert metric units to customary?
Multip
6 yd
You need to convert from yards to feet.
We know that 1 yd. = 3 ft. So how many ft. is 6 yds.?
Oct 24­3:00 PM
Oct 24­3:01 PM
2
conversions.notebook
October 22, 2014
Henry measured his computer desk at home. The desk measured 72 inches across and 36 inches long.
Caitlyn runs 1 mile everyday. What is the distance she runs in one week, in feet?
Answer
Convert inches to feet.
12 in. = 1 ft.
12 in. = 1 ft.
1 mile = 5,280 72 inches divided by 12 = 6 ft.
feet
72 in. = 6 ft.
36 inches divided by 12 = 3 ft.
Answer
What are the desk's measurements in ft.?
Henry's desk measures 6 ft. by 3 ft.
Oct 24­3:01 PM
Oct 24­3:02 PM
How many centimeters are in a standard ruler? (1 foot)
You can use ratios to convert US Customary Units into Metric Units.
Some common conversions you should know:
We know that there are 12 inches in 1 foot, and 1 inch = 2.54 cm
30.48 cm
1 in = 2.54 cm
1 ft = 0.3 m
1 kg
1 mi = 1.6 km
1 lb = 0.45 kg
Answer
1 gal = 3.79 l (liters)
1 inch = 2.54 cm
1 foot = 12 x 2.54 cm = 30.48 cm
There are 30.48 cm in a standard ruler.
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Oct 24­3:04 PM
Oct 24­3:05 PM
Linda's chihuahua weighs 5 lbs. Carlos ran a 5k race. A 5k race is 5 km long. How many miles is this?
What is the dog's weight in kg?
We know that 1 mi = 1.6 km
We know that:
Oct 24­3:05 PM
1 mi = 1.6 km
How many miles is 5 km?
1 lb = 0.45 kg
Divide 5 km by 1.6 km which is approximately 3.1 miles.
5 lb = how many kg?
Whenever you hear that someone has run a 5k, they ran a 3.1 mile long race.
Answer
3.125 mi
Answer
So how many miles is 5 km?
1 lb = 0
5 lb = 0.45 x
Linda's dog
Oct 24­3:06 PM
3
conversions.notebook
October 22, 2014
Sandy is making 3 gallons of apple cider. How many liters of apple cider will Sandy have?
120 lbs
Answer
3 gal = how many liters?
Answer
You know that 1 gal = 3.79 l
Oct 24­3:07 PM
Answer
Oct 24­3:06 PM
1 lb x =
54/0.45
1 mi = 1.6 km
2,800 = 1.6 x 2800 = 4506 km
D. 4,500
1 in = 2.54 cm
1 ft = 0.3 m
1 mi = 1.6 km
1 lb = 0.45 kg
1 gal = 3.79 l (liters)
Oct 24­3:08 PM
Oct 22­11:10 AM
4