MEASUREMENTMr. Peterson

SCIENCE

Center Grove Middle School North

Measurement

Describe the world using numbers Types of Measurement include:

Distance, time, speed, volume, mass…

Measurement can also help describe events

Metric System

Called the International System of Units or SI Decimal system based on 10’s

Prefixes include:Milli (1/1000th)Deci (1/10th)Kilo (1000)

Metric System

Used by scientists all over the world to measure length, volume, mass, weight, density, and temperature.

King Hector Doesn’t Usually Drink Chocolate Milk

KILO HECTO DEKA UNIT DECI CENTI MILLI

Precision and Accuracy

Precision is the closeness of repeated measurements to each other.

Accuracy is the closeness of a measured or derived data value to its true value.precise = repeatable

accurate = true

Practice

Precision and Accuracy

Significant digits are necessary when calculating DON’T COUNT Zeros at the end of the number

without a decimal (ex. 1300) OR Zeros at the beginning of a decimal (ex. 0.0025).

When adding or subtracting, use the smallest number you use.

Example: 4.587

+ 3.1

7.687Answer in significant digits = 7.7

significant digits = 4

significant digits = 2

Precision and Accuracy

Scientific notation is used so large numbers are easier to understand. Move the decimal point until only 1 nonzero

number remains on the left. Count the number of places you moved the decimal and use that number as a power of ten

Examples: 85670000000 = 8.567 x 1010

0.00000045 = 4.5 x 10-7

43289 = 4.3289 x 104

Length

Distance from one point to another METER (M) is the basic unit

1M = 100cm 1M = 1000mm 1km = 1000M

Volume

Amount of space an object takes up Liter (L) is the basic unit of LIQUID volume Cubic centimeter (cm3) is the basic unit of

SOLID volume

Mass

Amount of matter in an object Gram (g) is the basic unit

Weight

Amount of attraction between two objects due to gravity

Newton (N) is the basic unit MASS AND WEIGHT ARE NOT THE SAME!

Density

Mass per unit volume of a substance g/mL is the basic unit Formula: Density = Mass divided by Volume

Density = g/mL Density of water is 1gram/milliliter If an object’s density is less then one it will float. If an object’s density is greater then one it will

sink.

Temperature

Measure of hotness and coldness Celsius (C°) is the basic unit Water freezes at 0° degree Celsius and boils at

100° degrees Celsius.