Converting measurement units (age 9+)
Know relative sizes of measurement units within one system (km/m/cm/mm, kg/g, l/ml, hr/min/sec); convert between different metric units and express measurements in terms of a smaller unit; record equivalents in conversion tables
What a learner can do afterwards
- Convert 3.5 km to 3,500 m
- Complete a conversion table for cm and mm: (1,10), (2,20), (3,30)...
- Express 2 kg 350 g as 2,350 g
The lesson
You already know how to change between measurement units. Now you'll work with bigger numbers and decimals, and combine two units into one, like turning 2 kilograms 350 grams into a single number of grams.
To turn a bigger unit into a smaller one, multiply. A kilometer is 1,000 meters, so 3.5 km becomes 3.5 times 1,000, which is 3,500 m. The same rule works for kg to g and l to ml. For cm to mm, multiply by 10 instead.
A bag of flour weighs 2 kg 350 g. To write it only in grams, change the 2 kg to 2,000 g, then add the extra 350 g. 2,000 plus 350 makes 2,350 g.
Watch your zeros. Multiplying by 1,000 adds three zeros (or moves the decimal point three places right). Multiplying by 10 moves it just one place.
To change to a smaller unit, multiply by 10, 100, or 1,000, then add on any extra amount carefully.
Watch it
Where it sits
Where this leads
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.