Minds On

Which container will hold the most water?

There are three containers that can be filled with water.

3 containers: a plastic bottle, a large glass, and a metal water bottle

Let's think about the following questions:

  • Which container do you estimate will hold the most water?
  • How could you check whether your estimation is correct?
  • How could you measure the amount of water that will fit into each container?

Explain your thinking. Record your ideas in a notebook or a method of your choice.

Action

Task 1: What is capacity?

Capacity is the greatest amount that a container can hold.

Capacity is usually measured in units of litres (L) or millilitres (mL).

Litres are generally used for larger containers while millilitres are used for smaller containers.

List some objects or containers that are measured in L and in mL and sort them into a table of litres and millitres or record your ideas using another method.

L mL

Task 2: Reasonable units

Decide whether mL or L should be used to measure the following items: a milk carton, a car gas tank, a small tube of lotion, an orange juice carton, a mop bucket, and a mug.

Record your ideas in a notebook or a method of your choice.

Press each of the following items to compare your answers.

Milk is usually measured and sold in litres.

Gas is measured in litres.

These types of products are measured in millilitres.

Individual drink containers are measured in millilitres.

The water in the bucket would be measured in litres.

An individual mug of coffee would be measured in millilitres.

Task 3: Units and conversion

Even though there are only two commonly used measurements for capacity, the same set of metric prefixes apply to capacity that applied to measurements of length.

The litre is the base unit for measuring capacity, like the metre is the base unit for measuring length. Base units correspond to the one’s column. Millilitres correspond to millimetres because they fall in the thousandths place value column. That means that 1 litre is equal to 1,000 millilitres. The common prefixes used in capacity measurement are: Kilo-, Hecto-, Deca-, Deci-, Centi-, and Milli- as shown in the following table.

Think about strategies

  1. Using the place value table, what operation you would use to convert from L to mL or from mL to L?
  2. If mL is a smaller unit than L, should there be more or less mL in each L?

Consider the answers to these questions and determine a strategy that you could use to convert between L and mL.

Strategy 1: If every L has 1,000 mL in it, that means you need to multiply the number of L by 1,000 to determine the capacity in mL. Conversely, if you are given a capacity in mL, you need to divide by 1,000 to determine the capacity in L.

Strategy 2: Using the place value chart, you can move the decimal the correct number of places to the left or right.

When converting from the ones column (the base unit, litres) to the thousandths column (millilitres), move the decimal 3 places to the right. That might mean adding some 0’s when converting from L to mL. When converting from the thousandths column (mL) to the ones column (L), move the decimal 3 places to the left. For example, 1,000 mL becomes 1 L.

Which strategy do you think is most appropriate? Explain your thinking.

Record your ideas in a notebook or a method of your choice.

Task 4: Conversion practice

After answering the questions in your notebook, press the ‘Show Answer’ button to reveal the solutions.

A) Convert the following measurements of capacity into L.

  • Question 1) 5,884 mL
  • Question 2) 38 mL
  • Question 3) 4,500 mL
  • Question 4) 75,000 mL

Solution 1) 5,884 mL = 5.884 L

Solution 2) 38 mL = 0.038 L

Solution 3) 4,500 mL = 4.5 L

Solution 4) 75,000 mL = 75 L

B) Convert the following measurements of capacity into mL.

  • Question 1) 9 L
  • Question 2) 27 L
  • Question 3) 4.6 L
  • Question 4) 0.05 L

Solution 1) 9 L = 9,000 mL

Solution 2) 27 L = 27,000 mL

Solution 3) 4.6 L = 4,600 mL

Solution 4) 0.05 L = 50 mL

C) In each pair, determine which measurement is larger by using conversions. Complete each sentence with a greater than (>), less than (<), or equal to (=) sign.

  • Question 1) 500 L (Blank) 5,000 mL
  • Question 2) 3,500 mL (Blank) 4 L
  • Question 3) 85,500 mL (Blank) 85 L
  • Question 4) 900,000 mL (Blank) 900 L

Solution 1) 500 L > 5,000 mL

Solution 2) 3,500 mL < 4 L

Solution 3) 85,500 mL > 85 L

Solution 4) 900,000 mL = 900 L

Reflect on the practice questions that you have completed.

  1. Which strategy did you use?
  2. Why did you need to use conversions to figure out which measurement was greater?

Record your ideas in a notebook or a method of your choice.

Task 5: Conversion practice with word problems

Young girl holds a cup of tea in one hand, and a teapot in the other

Complete the following questions with a partner, or independently. After answering the questions in your notebook, press the ‘Show Answer’ button to reveal the solutions.

Record your answers in a notebook or a method of your choice.

  • Question 1) There is a cup that holds 500 mL and a jug with 2 L of tea. How many cups of tea can be filled with the 2 L jug?
  • Question 2) There are 4 containers each filled with 250 mL of liquid soap. How many L of soap are there in total?
  • Question 3) A rain barrel needs to be emptied. The barrel holds 150 L of water. There is a jug that holds 750 mL of water. How many full jugs will the rain barrel fill?

Solution 1)
2 L = 2,000 mL, so the jug contains 2,000 mL of tea. Therefore, the jug can fill 2,000 ÷ 500 = 4 cups.

Solution 2)
There is 4 × 250 mL = 1,000 mL = 1 L of liquid soap.

Solution 3)
150 L = 150,000 mL, so there is 150,000 mL of water in the barrel. Therefore, the rain barrel will fill 150,000 ÷ 750 = 200 jugs.

Consolidation

Make your own word problems

Create two word problems that involve capacity.

Each problem must include a conversion of units. Calculate the answers to your word problems, showing all of the steps required to solve the problem.

Record your thinking using a method of your choice.

Thinking back

Consider the following questions to reflect on your learning. You can record your responses using a method of your choice.

  1. How would you explain converting measurements of capacity to someone?
  2. When might someone use these skills in real-life situations? What jobs would these skills be useful for?

Reflection

As you read through these descriptions, which sentence best describes how you are feeling about your understanding of this learning activity? Press the button that is beside this sentence.

I feel...

Now, record your ideas using a voice recorder, speech-to-text, or writing tool.

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