Measurements I can use the SI units of measurement I can convert using conversion factors

Reliability in measurements  Precise measurements will give the same results again and again  Accuracy is how close you are to the accepted value

SI Units  SI units a revised form of the metric system  SI base units are fundamental physical units  SI derived units are combinations of SI base units

Identify the metric units for  Mass  Length  Volume  Temperature  Time

Metrics  Do you recall King Henry does back delicious corn muffins.  Kilo  Hecto  Deka  Base  Deci  Centi  Milli

K, H, D, B, d, c, m  When moving to the right, units get smaller so your number larger. Move the decimal RIGHT  When moving to the left, units get larger, so your number gets smaller. Move the decimal LEFT

Practice  950 g kg .075m cm  4,500mg g

Conversion Factors  A conversion factor is a ratio to convert a quantity in a given unit to an equal quantity with a different unit.  They are derived from the units used in the problem Example if the units used are mile and feet then this becomes the conversion factor Example if the units used are mile and feet then this becomes the conversion factor

Fractions  What is 3/4 multiplied by 2/3?  The way we cancel in multiplying fraction is the way that units cancel in conversions factors

Confused? Lets try an example  If you have 39 quarters, how many dollars is this?  How do these amounts compare?  The way the compare is the conversion factor.  The units you are given is called the given. The units you are finding is the unknown.  The equation looks like this:  Given units X Desired units/Given units = Desired units

Always Remember  Determine the given and the unknown  Determine the mathematical relationship between them (CONVERSION FACTOR)  Set up the units and make sure they cancel correctly  Plug in the numbers and solve

Practice  How many seconds are in 45 min?  How many seconds in 82 min?  How many hours are there in 9834 minutes?  How many inches in 3.66 feet?

Lets try with metrics  If there are 1000 mm in one meter, then how many meters are there in 55mm?  How many meters are in 300cm?  How many meters in 88hm?

Sometimes multiple steps are needed  Example:  How many seconds in 5.3 hours?

Practice  How many centimeters are in 13 feet? (1 in =2.54 cm)

Practice  How many centimeters are in 1.3 miles? (1 mile = 5280 ft) (1 mile = 5280 ft) (1 inch = 2.54 cm) (1 inch = 2.54 cm)