1. Units of Weight

2. There are 2 main units of customary weight:
How Heavy is it?
There are 2 main units of customary weight:
Pounds
Ounces

3. Ounces are used to weigh light things
A letter is about an ounce.

4. Pounds are used to weigh heavy things
Your Open Court book weighs about a pound.

5. The abbreviation for pound is lb.
The baby weighs
15 lbs.

6. The abbreviation for ounce is oz.
The pencil weighs about 5 oz.

7. Conversions
1 lb = 16 oz.
One way to remember is that lb sort of looks like 16! lb 16

8. Tom had 4 lbs. of fruit. Sam had 36 oz. of fruit. Who had more?
Step 1: What do I know?
I know that they both need to be the same unit because I can’t compare different units.

9. Step 2: Choose the lower unit and convert.
Since there are oz and pounds, ounces are the smaller unit. I will convert to ounces.

10. Since I know that 1 lb = 16 oz, I can make a table.
pounds 1
ounces 16

11. pounds 1 2 3 4
ounces 16 32 48 64
4 pounds is equal to 64 oz.

12. Tom had 4 lbs. of fruit. Sam had 36 oz.
of fruit. Who had more?
Since 4 pounds = 64 oz, then Tom had more, because 64 oz > 36 oz.

13. Since 16 oz is one pound, then…
I can also DRAW A PICTURE to convert measurement.
Since 16 oz is one pound, then…
16 oz
16 oz
16 oz
16 oz
= 64 OR 4 x 16 = 64

14. Metric Measurements Gram—used for light items
A paper clip is about a gram.

15. Kilogram—used for bigger things
Your math book is about a kilogram.

16. Abbreviations
Gram g
Kilograms kg
Remember…1,000 g = 1 kg

17. Conversions Convert to lowest measure… Grams!
Mary needed 5,000 g of flour for the recipe. She had a bag of 4 kg. Does she have enough?
Convert to lowest measure… Grams!

18. Draw a Picture! Since 1 kg = 1,000 g, then 4 kg = 4,000g 1,000 g

19. So…she does not have enough. She only has 4,000 kg!
Mary needed 5,000 g of flour for the recipe. She had a bag of 4 kg. Does she have enough?
So…she does not have enough. She only has 4,000 kg!