Measurements

Metric measurement is the tool used in science Metric measurement is the tool used in science. Because of its ability to measure very small, microscopic samples, the metric units afford the scientist very accurate numbers. There are three metric units – liter, gram, meter. Each measures a specific property of matter. The metric system is based on powers of ten, so it is very easy to use. Just remember to multiply or divide by ten or a power of ten.

Kilo: 1000 of any unit unit gram, liter, meter Deci: 0.1 of any unit It will take 10 decis to make up 1 unit Centi: 0.01 of any unit Milli: 0.001 of any unit Micro: 0.000001 Nano: 0.0000000001 of any unit

So: if we want to move from one value in the metric scale to another value, we multiply or divide by powers of 10. What does this mean, Well….. Let’s say we know that we have 100 cm of string and we want to know how many meters that is. First decide in which direction is our conversion-are we going from a larger unit to a smaller unit or from a smaller unit to a larger unit. Since cm are smaller than meters, we are moving from smaller to larger and therefore we divide. Now what do we divide by??? Go back to what you know. How many centis fit in a unit? 100 cm = 1 m. This conversion stays constant - it will never change. Ok now we know that we have to divide by 100. 100cm/100cm = 1

Easy right. Okay let’s try something more difficult. What if we have 17.5 cm of string. How many meters is that going to be? Remember in what direction are we going-smaller to bigger or bigger to smaller? Like before we are going from smaller to bigger so we will divide. The conversion stays the same: 100 cm= 1m To convert 17.5 cm into meters we will divide by 100: 17.5/100 = 0.175 m

We have converted values from smaller to bigger. Let’s go the other way. How many mm are there in 3 m? Remember, in which direction are we going- smaller to bigger or bigger to smaller? There are 1000 mm in 1 m so the meter is bigger than the mm. We will be converting from bigger to smaller. We will multiply. But by what? Remember the conversion: 1000 mm = 1m We need to multiply by 1000. So: 3m x 1000 = 3000 mm.

How many cm are there in 24.2 m? Remember, step 1: in which direction are you going? Step 2: what is the conversion factor for converting 1 m into cm? Step 3: multiply or divide using the conversion factor.

Some examples: 35 kg = dg .3 dl = ml 16.2 cm = mm .08 g = cg

Answer sheet 350,000 300 162 8