Metric Units of Length

Benchmarks are measurements that can be used to estimate the length of other objects

The thickness of a dime is used as a benchmark for a millimeter

The width of a fingernail is used as a benchmark for a centimeter

The width of a CD case is used as a benchmark for a decimeter and the width of a single bed is used as a benchmark for a meter

The distance around a city block is used as a benchmark for a kilometer

To convert a measure in one unit to another unit, count the number of places the unit lies to the left or right of the given unit

A unit lying to the left of the given unit is bigger. Multiply the bigger unit by the conversion factor to convert it to the smaller unit

A unit lying to the right of the given unit is smaller. Divide the smaller unit by the conversion factor to convert it to the bigger unit

The word 'deci' refers to 1/10, 'centi' refers to 1/100, 'milli' refers to 1/1000. The word 'deka' refers to 10, 'hecto' refers to 100 and 'kilo' refers to 1000

To compare various measurements in different units, convert all the measurements into a common unit

To find the quotient of two measurements, divide the numbers and reduce the units

To find the product of two measurements, multiply both the numbers and the units

To add or subtract two measurements, convert both the measurements to a common unit