Metric Measurement

MeasurementMetric System –

A. Why we use the metric system:

1. Universal system of measurement having standard units.

All scientists around the world use the same system.

2.Accurate

3. Easier to use – because it’s units of ten

(use decimals) NO FRACTIONS

Questionsanswer this question on your note page

What are three reasons we use the metric system?1.

2.

3.

Questionsanswer this question on your note page

• What are three reasons we use the metric system?1. All scientists use the metric system

2. Easier to use because it’s units of ten

3. Accurate

B.

B. Basic Metric Units

1. Length (or distance) - meter (m)

2. Mass - gram (g)

3. Volume - liter (L)

4. Temperature – Celsius (°C)

C. Tools used in Laboratory

1. Length or distance– meter stick or metric ruler

2. Volume –

a. liquid volume - graduated cylinder

– read the bottom of the curve called the meniscus for accuracy

b. volume of a regular solid object– length x width x height

OR

c. volume of an irregular solid object– immerse the object in a

water-filled graduated cylinder and measure the rise.

3. Mass – triple beam balance or gram scale

4. Temperature - thermometer

Measuring Mass

Top Image: http://www.southwestscales.com/Ohaus_Triple_Beam_750-SO.jpgBottom Image: http://www.regentsprep.org/Regents/biology/units/laboratory/graphics/triplebeambalance.jpg

We will be using triple-beam balances to find the mass of various objects.

The objects are placed on the scale and then you move the weights on the beams until you get the lines on the right-side of the scale to match up.

Once you have balanced the scale, you add up the amounts on each beam to find the total mass.

What would be the mass of the object measured in the picture?

_______ + ______ + _______ = ________ g

Measuring Mass

Top Image: http://www.southwestscales.com/Ohaus_Triple_Beam_750-SO.jpgBottom Image: http://www.regentsprep.org/Regents/biology/units/laboratory/graphics/triplebeambalance.jpg

We will be using triple-beam balances to find the mass of various objects.

The objects are placed on the scale and then you move the weights on the beams until you get the lines on the right-side of the scale to match up.

Once you have balanced the scale, you add up the amounts on each beam to find the total mass.

What would be the mass of the object measured in the picture?

300 + ______ + _______ = ________ g

Measuring Mass

Top Image: http://www.southwestscales.com/Ohaus_Triple_Beam_750-SO.jpgBottom Image: http://www.regentsprep.org/Regents/biology/units/laboratory/graphics/triplebeambalance.jpg

We will be using triple-beam balances to find the mass of various objects.

The objects are placed on the scale and then you move the weights on the beams until you get the lines on the right-side of the scale to match up.

Once you have balanced the scale, you add up the amounts on each beam to find the total mass.

What would be the mass of the object measured in the picture?

300 + 70 + _______ = ________ g

Measuring Mass

Top Image: http://www.southwestscales.com/Ohaus_Triple_Beam_750-SO.jpgBottom Image: http://www.regentsprep.org/Regents/biology/units/laboratory/graphics/triplebeambalance.jpg

We will be using triple-beam balances to find the mass of various objects.

The objects are placed on the scale and then you move the weights on the beams until you get the lines on the right-side of the scale to match up.

Once you have balanced the scale, you add up the amounts on each beam to find the total mass.

What would be the mass of the object measured in the picture?

300 + 70 + 3.3 = ________ g

Measuring Mass

Top Image: http://www.southwestscales.com/Ohaus_Triple_Beam_750-SO.jpgBottom Image: http://www.regentsprep.org/Regents/biology/units/laboratory/graphics/triplebeambalance.jpg

We will be using triple-beam balances to find the mass of various objects.

The objects are placed on the scale and then you move the weights on the beams until you get the lines on the right-side of the scale to match up.

Once you have balanced the scale, you add up the amounts on each beam to find the total mass.

What would be the mass of the object measured in the picture?

300 + 70 + 3.3 = 373.3 g

Measuring Mass – Triple-Beam Balance

1st – Place the film canister on the scale.

2nd – Slide the large weight to the right until the arm drops below the line. Move the rider back one groove. Make sure it “locks” into place.

3rd – Repeat this process with the top weight. When the arm moves below the line, back it up one groove.

4th – Slide the small weight on the front beam until the lines match up.

5th – Add the amounts on each beam to find the total mass to the nearest tenth of a gram.

Questionsanswer these questions on your note page

What do each of the following tools measure?

1. graduated cylinder _____________________

2. meter stick or metric ruler _______________

3. triple beam balance or gram scale _________

4. thermometer __________________________

Questionsanswer these questions on your note page

What do each of the following tools measure?

1. graduated cylinder volume

2. meter stick or metric ruler length or distance

3. triple beam balance or gram scale mass

4. thermometer temperature

D. When measuring smaller or larger

amounts than the basic units use the appropriate power of ten.

• We can then measure smaller amounts with units such as millimeters or centimeters [like the height of a book] and larger amounts with units such as kilometers [like the distance from North to Merlin].

1. Common metric units

Prefix Abbreviation Meaning

kilo- k 1000

Basic Unit (m, L, g) L, m, g 1

centi- c .01

milli- m .001

Questionsanswer these questions on your note page

1. What does the prefix kilo mean?

2. What basic unit do we use for measuring length?

3. What is the abbreviation for the unit in question 2?

Questionsanswer these questions on your note page

1. What does the prefix kilo mean?1000

2. What basic unit do we use for measuring length?

Meter

3. What is the abbreviation for the unit in question 2?

m

2. Metric values – we know metric units are based on units of ten, so adjusting between large and small units becomes easier depending on what you are measuring.a. 10 mm = 1 cm or 10 mg = 1 cg or 10 mL = 1 cL

b. 100 cm = 1m or 100 cg = 1 g or 100 cL = 1 L

c. 1000 m = 1 km or 1000 g = 1 kg or 1000 L = 1 kL

E. Conversions [use your Conversion Chart to make things simple]

1. Changing units

a. change smaller unit to larger unit

353 mm = 35.3 cm– Move the decimal one place to the left– math problem (division)– 353 divided by 10 353/ 10 =35.3

Questions

1. Convert 689 mL to L =

2. Convert 4.3 cg to kg =

Questions

1. Convert 689 mL to L =

.689 L

2. Convert 4328 g to kg =

4.328 kg

b. change from larger to smaller units

2.24 kg = 2240g– move the decimal three places to the

_right__– math problem (multiplication)

2.24

x 1000

2240.00

Questions

1. Convert 36.5 kg to g =

2. Convert 78 m to cm =

Questions

1. Convert 36.5 kg to g =

36,500g

1. Convert 78 m to cm =

7800cm