Metric Metric Conversions & Conversions &

RoundingRounding

SI Prefixes ChartSI Prefixes ChartPrefixPrefix SymbSymb

ololMeaningMeaning

kilo-kilo- kk 1,0001,000

hecto-hecto- hh 100100

deka-deka- dada 1010

basic unitbasic unit m, g, m, g, literliter

11

deci-deci- dd .1.1 (one tenth)(one tenth)

centicenti cc .01.01 (one (one hundredth)hundredth)

millimilli mm ..001001 (one (one thousandth)thousandth)

ConversionsConversions To convert to a larger unit, move the decimal place to To convert to a larger unit, move the decimal place to

the left (divide)the left (divide) To convert to a smaller unit, move the decimal place To convert to a smaller unit, move the decimal place

to the right (multiply)to the right (multiply)

KKing ing HHenry enry DDied of ied of DDrinking rinking CChocolate hocolate MMilk ilk

MMmmmmmm i e e e e i ii e e e e i i

l c k c n l cl c k c n l c

o t a i t l o t a i t l rr

o i i oo i i o

PracticePractice10 grams = ? kilograms10 grams = ? kilograms

.01kg.01kgMove the decimal three places to the leftMove the decimal three places to the left

56 meters = ? centimeters56 meters = ? centimeters5,600 cm5,600 cm

Move the decimal two places to the rightMove the decimal two places to the right

876 centimeters = ? kilometers876 centimeters = ? kilometers.00876 km.00876 km

Move the decimal five places to the leftMove the decimal five places to the left

Common SI ConversionsCommon SI ConversionsLengthLength VolumeVolume

kilometer (km) = kilometer (km) = 1,000 m1,000 m

kiloliter (kL) = kiloliter (kL) = 1,000 L1,000 L

meter (m) = 100 meter (m) = 100 cmcm

Liter (L) = 1,000 Liter (L) = 1,000 mL mL

centimeter (cm) centimeter (cm) = .01 m= .01 m

centiliter (cL) centiliter (cL) = .01 L= .01 L

millimeter (mm) millimeter (mm) = .001 m= .001 m

milliliter (mL) milliliter (mL) = .001L= .001L

MassMass

Kilogram (kg) = Kilogram (kg) = 1,000 g1,000 g

Gram (g) = 1,000 Gram (g) = 1,000 mgmg

Milligram (mg) Milligram (mg) = .001 g= .001 g

Brain Break! Brain Break! Lets play Gotcha!Lets play Gotcha!

Adding or Subtracting Adding or Subtracting NumbersNumbers

The answer should have the The answer should have the SAMESAME # # of of decimal placesdecimal places as the as the measurement measurement with the least number with the least number of decimal places. of decimal places.

For example: For example:

5.3 + 21.94 = 27.24 5.3 + 21.94 = 27.24

= 27.2 (One decimal place)= 27.2 (One decimal place)

2.25 + 3.1 = 5.35 2.25 + 3.1 = 5.35

= 5.3 (One decimal place) = 5.3 (One decimal place)

Multiplying or Dividing Multiplying or Dividing NumbersNumbers

answer should have the same # of digits answer should have the same # of digits as the measurement with the as the measurement with the least least amount of digitsamount of digits. .

For example:For example:

2.25 x 3 = 6.75 (3 only has one digit)2.25 x 3 = 6.75 (3 only has one digit)

= 7= 7

3.57 x 3.456 = 12.34 (3.57 has three 3.57 x 3.456 = 12.34 (3.57 has three digits)digits)

= 12.3= 12.3

RoundingRounding!!In Labs, you will usually have to round In Labs, you will usually have to round

measurements. measurements.

Round to the tenths place?Round to the tenths place?

10.56710.567

= 10.6= 10.6(1 place past the decimal)(1 place past the decimal)

Round to the hundredths place?Round to the hundredths place?

10.56710.567

=10.57=10.57(2 places past the decimal)(2 places past the decimal)

Accuracy vs. Accuracy vs. Reproducibility/PrecisionReproducibility/Precision Accuracy-Accuracy-

How close a measurement is to its true or How close a measurement is to its true or actual value.actual value.

Reproducibility/PrecisionReproducibility/Precision--

How close a group of measurements are to How close a group of measurements are to each othereach other

The textbook definition of The textbook definition of

precision is confusing. Don’t worry precision is confusing. Don’t worry

about it. Reproducibility and about it. Reproducibility and

Precision are the same.Precision are the same.

Let’s ReviewLet’s ReviewWith your partner, answer the following With your partner, answer the following

questions…questions…1.1. If you are converting to a larger unit, move the If you are converting to a larger unit, move the

decimal place to the ____________.decimal place to the ____________.2.2. If you are converting to a smaller unit, move If you are converting to a smaller unit, move

the decimal place to the ____________.the decimal place to the ____________.3.3. How many grams in a kilogram?How many grams in a kilogram?4.4. How many milligrams in a gram?How many milligrams in a gram?5.5. Rounding to the tenths place = ____ places past Rounding to the tenths place = ____ places past

the decimal? Hundredths place = _____ places.the decimal? Hundredths place = _____ places.6.6. Using a metric ruler with millimeter markings, Using a metric ruler with millimeter markings,

you measure the width of a book to be 14.23 you measure the width of a book to be 14.23 cm. How many digits can you be certain of? cm. How many digits can you be certain of? How many sig figs?How many sig figs?