Grade 3Math
How Units of Length, Weight, and Volume Are RelatedConnect kilo, centi, milli, and deci
Units of length, weight, and volume have letters in front of them, like "kilo" and "milli." What these letters mean is the same for every unit. Let's find the rules and connect the units.
The narration and the pictures are in Japanese. You can hear the same words that are used in class at a Japanese school.
- Video
- 2:45（10 scenes）
- Problems
- 3 problems
Open this lesson in Japanese（長さ・重さ・かさの 単位の 関係）
Let's try
Write the math sentence in your notebook first, then open the answer.
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1How many g is 4 kg?
Hint
Remember how many g are in 1 kg.
Answer
Kilo means 1000 times, so 4 × 1000 = 4000. It is 4000 g.
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2How many mL is 5 L?
Hint
Milli is one of how many equal parts of 1 L?
Answer
1 L = 1000 mL, so 5 × 1000 = 5000. It is 5000 mL.
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3How many kg and g is 2500 g?
Hint
Change every 1000 g into 1 kg.
Answer
1000 g is 1 kg, so 2500 g = 2 kg 500 g.
Words in this lesson
- kilo キロ
- Letters put in front of a unit. They mean 1000 times the basic unit.
- milli ミリ
- Letters put in front of a unit. They mean one of 1000 equal parts of the basic unit.
- centi センチ
- Letters put in front of a unit. They mean one of 100 equal parts of the basic unit.
- deci デシ
- Letters put in front of a unit. They mean one of 10 equal parts of the basic unit.
- using the same unit 単位をそろえる
- Showing amounts in the same unit so that you can compare or calculate them.
For parents and guardians
- Units of length, weight, and volume are learned little by little in 2nd and 3rd grade. This page is a summary that connects these units so that children notice rules such as "kilo is 1000 times" and "milli is one of 1000 equal parts." The order of topics and the range of units covered differ slightly between textbooks.
- Children often mix up "which unit is bigger" and "how many times bigger." Checking with real things around you, such as a 1 kg bag of sugar or a 1 L milk carton, makes it easier to get a feel for kilo and milli.
- Calculations with mixed units (such as subtraction with borrowing) are not covered on this page. Here we stop at changing units and using the same unit to compare.