1. Approximating vs. Estimating
Approximating - Simplifies a number
Example: The exact measurement to a side of a square is 4.15 inches but we can approximate it to be 4 inches.
Estimating - The operation using the approximated numbers
Example: We estimate the area of the square by using the approximated value to find the area of the square
4 inches x 4 inches = 16 inches2

2. Accuracy vs. Precision In relation to Pi, which is 3.14159265358979.
3.14 is an "accurate" approximation to Pi. But it is not very precise.
is a very "precise" approximation to Pi, but it is not accurate,
is both accurate and precise.

3. Precise in Measurements
The smallest unit on a measuring instrument
This graduated cylinder's smallest marks are of 10 mL.
Therefore, the precision of this instrument is 10 mL.
This protractor's smallest marks measure 1 degree.
Therefore, the precision of this instrument is 1 degree

4. Guided Practice (5 min.)
Answer the questions in regards to precision and accuracy!

5. Guided Practice Review!
Determine if it would make more sense to estimate this number or approximate it:
The amount of people on a plane
The cost of groceries
Number of players on a team
Total amount of money earned from an hourly job
The temperature outside
Amount of time spent doing homework
The average of 5 of your friends’ height
Length of a field
Suppose you measured an object. Determine if the value you received is precise, accurate or both:
True value = 5, Value you receive =
True value = 3, Value you receive = 3.1
True value = , Value you receive is

6. Identify the precision of the measuring instruments

7. Let’s get to know our units!

8. Miligram Small objects Things we measure in milligrams:
A human eyelash is
equal to 1 miligram!
Things we measure
in milligrams:
Vitamins
Medication
Feather

9. Grams / Ounces A little bigger than a miligram A paper clip = 1 gram
A CD or a AA battery = 1 ounce
Things we measure in grams
and ounces:
A roll of quarters
A doorknob
Golf ball
Bar of soap

10. Pound / Kilogram Bigger than grams People Packages
A person is about 170 pounds!
A person is about 77 kilograms!
A package may weigh about 10 pounds.

11. Tons Very large things Trucks Buildings
A mack truck weighs about 9-12 tons!
1 ton = 2000 pounds

12. Measuring Length!

13. Milimeters Very small items A grain of sugar is about 1 mm!
Your nails are about 1 mm thick

14. Centimeters A little bit bigger 1 centimeter is about
the width of a pen or
pencil!
The width of your finger is about 1 cm.

15. Inches 1 inch = the length of a paper clip!
The last joint of your finger or thumb is about 1 inch
Objects we can measure in inches:
A notebook
Your hand

16. Foot We measure the following objects with feet: The length of a table
A window in your home
A foot is equivalent to a standard ruler!

17. Yard/Meter The distance across a football field
A yard stick is equivalent to 1 yard.
A football field is about 120 yards!

18. Kilometers / Miles The distance you run in a race
The distance you drive in a car
The distance between Morrow High School and Churches Chicken is 1 mile
The distance between Morrow High School and the Morrow Library is about 1 kilometer
The distance from Morrow to Atlanta is about 15 miles.
A person walks 20 minutes per 1 mile and 12 minutes per 1 kilometer.

19. Measuring Volume!

20. Milileters
Eye Drops
20 eye drops = 1 ml

21. Quarts/Cups/Pint Amounts used when baking/Cooking
Pint < cup < quart

22. Liters/Gallons A big bottle of soda A bucket of water
The big bottle of coke = 2 liters
The big milk carton is 1 gallon

23. Guided Practice (20 minutes)

24. Guided Practice – Review!
Determine which has a greater value:
10 Miles per hour vs. 10 feet per hour?
5 Feet per second vs. 5 Minutes per second
10 dollars per hour vs. 10 dollars per minute
1 Mile per day vs. 1 mile per week
Determine whether the selected measurement is crazy, so-so, or if it makes sense. If it is crazy or so-so provide a better unit measurement option:
Measuring a mouse in inches
Measuring the distance from the MHS to AMC theater in inches
Measuring the height of a ninth grader in cups
Measuring the speed of a human in a 100 yard dash marathon in miles per hour
Measuring the length of the field in miles
Measuring the water in a pool in cups

25. Guided Practice Choose the most appropriate measurement
The length of a door _________________
The weight of a bag of rice _____________
The distance from home to school ________________
The length of your notebook___________
The weight of a bowl of cereal__________
The volume of eye drops______________
The volume of a bottle of shampoo______
The length of a playground____________

26. Independent Practice Make sure you JUSTIFY your answers
For example: I believe that a swimming pool should be measured in kiloliters because a liter is used to measure things that are much smaller such as a bottle of soda. A kiloliter would be the next biggest unit of measurement.

27. Exit Ticket
What would be the approximate measure for the volume of a bath tub of water? Give a value and a unit.
Would measuring the length of a book best be done in yards? If so, why? If not, what would be a better measure and why?
Which has a bigger value 50 kilometers per hour or 50 yards per hour?

28. Homework
Online!