Career Ready Math - Section 4.2 - Intro to the Metric System

Career Ready Math - Section 4.2 - Intro to the Metric System

Chapter 4

Intro to the Metric System

Metric System - international system of measurement that uses standard units and power-of-10 prefixes to indicate other units of measure.

International System of Units (SI) - a standard unit represents each type of measurement

base unit - unit used most often in practice meter for distance, gram for weight, and liter for volume

Identify Uses of Metric Measures

most common prefixes for units smaller than the standard unit are:

deci -  $\frac{1}{10}$ of               centi -  $\frac{1}{100}$  of            milli -  $\frac{1}{1000}$  of



most common prefixes for larger than the standard unit are:
deka - 10 times           hecto - 100 times          kil -1000 times

Fill in the Blank

Examples

Give the value of the metric unit using the standard unit (meter, gram, or liter)

1. kilometer =

Multiple Select

Give the value of the metric unit using the standard unit.

hectometer =

• 10 times 1 meter

• 100 times 1 meter

• 1000 times 1 meter

• $\frac{1}{10}$ of 1 meter

Multiple Choice

Example

Give the value of the metric unit using the standard unit (meter, gram, or liter)

3. centrigram =

• $\frac{1}{100}$ of a gram

• $\frac{1}{1000}$ of a gram

• $\frac{1}{10}$ of a gram

• 100 times a gram

Length

A meter is 39.37 inches which makes it 3.37 inches longer than a yard.

A kilometer is 1000 meters and is used for longer distances.

A centimeter is used to measure objects less than a meter in length.

A millimeter is used to measure objects smaller than a centimeter.

Weight or Mass

A gram is the mass of 1 cubic centimeter (cm³) of water at its maximum density.

A kilogram is 1000 grams. It is approximately 2.2 lbs.

A milligram is used to measure very small objects

Capacity or Volume

A liter is the volume of a cube 10cm on each edge. One liter is a little larger than a quart.

A milliliter has the volume of a cubic centimeter.

Multiple Choice

Example

Choose the most reasonable measurement from Pittsburgh,

Pennsylvania to Charleston, West Virginia

• 367 m

• 367 km

• 367 cm

• 367 mm

Multiple Choice

Which is the most reasonable measure for the weight of an adult woman?

• 56 g

• 56 mg

• 56 kg

• 56 dkg

Multiple Choice

Which is the most reasonable measure for a bottle of eye drops?

• 30 dL

• 30 dkL

• 30L

• 30 mL

Multiple Choice

Which of the following is the most reasonable measure for the weight of an aspirin?

• 352 mg

• 352 dg

• 352 g

• 352 kg

Convert from One Metric Unit to Another

1. Move the decimal to the left he corresponding number of places if you are moving from a unit on the right to one on the left.

2. Move the decimal to the right the corresponding number of places if you are moving from a unit on the left to one on the right.

Moving the Decimal

If you convert kilometers (km) to centimeters (cm), you move the decimal the number of spaces that you move across the place value chart. You can see it demonstrated in the photo.

You can watch the video to better help with the conversions:

• https://www.youtube.com/watch?v=ByaeaVG6J5k

• Worth noting that all his measurements are in terms of "meters" so that is why he uses the word "monkeys" in his pneumonic device.

• If you use "units" in place of "meters" in his device, you could remember "Ken has driven unicorns down country meadows."

Fill in the Blank

Find the missing measurement:

43 dkm = ________ cm

Multiple Choice

Find the missing measure.

2.5 dg = _______ mg

• 25

• 250

• 0.25

• 0.025

Multiple Choice

Find the missing measure:

2.78 cm = _______ dkm

• 27.8

• 0.278

• 0.0278

• 0.00278

Multiple Choice

Find the missing measure:

2,426 L = _______ kL

• 242.6

• 24.26

• 2.246

• 0.2246

Making Calculations

If the units match, we can add and subtract the measurements. If they do not match, then we need to make them match first.

Example:

8 L + 12 L = 20 L (can add because both units are Liters)

9 cm + 5 cm = 14 cm (can add because the units match)

17 g - 10 mg = ? (we need to convert grams to milligrams first)

Multiple Choice

Find the answer:

14 mm + 22 mm =

• Cannot add these together

• 36 mm

• 8 mm

• 26 mm

Multiple Choice

Find the answer:

28 cL - 15 cL

• 43 cL

• 13 cL

• 23 cL

• cannot subtract these units

To Add non-like measurements that can be converted to match

3 km + 18 m = ?

Convert one of the values to match the other:

3 km = 3000 m

3000 m + 18 m = 3018 m OR 3.018 km

Multiple Choice

Find the answer.

9 mL + 2 cL =

• 11 mcL

• 29 mL

• 29 cL

• 11 mL

Multiple Choice

Find the answer.

14 km - 34 hm

• -20 km

• -20 khm

• 10.6 km

• 13.66 km

Multiplying or Dividing Metric Units

If multiplying or dividing metric units with another number, perform the operation and then keep the units as your label.

Example:

James jogs 3.5 km each day. How many kilometers did he jog in a week?

3.5 km x 7 = 24.5 km

Example

Lindsay has 18.6 grams of sugar that she needs to separate into 8 bowls for a dinner party. How much sugar should she put in each bowl so they all have the same amount?

18.6  $\div$   8 = 2.325 g

Example

Sometimes you have the same units that you are dividing or multiplying.

Suppose you need to administer a 250-mg dose of ascorbic acid in 100-mg tablets. How many tablets are needed per dose?

 $\frac{250\ mg}{100\ mg}\ =\ 2.5\ tablets$ 

OR Sam is building a 3.2 m by 4.1 m platform. What is the area of the platform?

 3.2 m x 4.1 m = 13.12  $m^2$  

Multiple Choice

Four micrometers weighing 752 g each will fit into a shipping carton. If the shipping carton and filler weigh 217 g, what is the total weight of the shipment?

• 969 g

• 3,008 g

• 535 g

• 405 g

Multiple Choice

A 8 m board is to be cut into 5 equal parts. How long is each part?

• 3 m

• 16 m

• 1.6 m

• Cannot cut 8m into 5 parts

Multiple Choice

How many 32-g packages of seeds can be made from 2.4 kg of seed?

• None, there isn't enough seed

• 13 packages

• 75 packages

• 30 packages

Previous Example

You would need the units to match. Convert kg to g by multiplying 2.4x1000 = 2400

2400/32 =75 packages