Chapter 5 of 8

All 8 chapters
  1. 1Centimetres and metres, readunderstood
  2. 2Millimetres and kilometres, readunderstood
  3. 3Tenths and the decimal point, readunderstood
  4. 4Grams and kilograms, readunderstood
  5. 5Millilitres and litres, readunderstood
  6. 6Telling the time, readunderstood
  7. 7How long it takes, readunderstood
  8. 8Perimeter and area, readunderstood

M2.6.5 Chapter 5

Millilitres and litres

How do I read how much water is in a jug?

Your guess

Pick one before you read on. It is fine to be wrong.

Your guess

  • You picked A. Read on. At the end, the chapter comes back to your guess.

  • You picked B. Read on. At the end, the chapter comes back to your guess.

  • You picked C. Read on. At the end, the chapter comes back to your guess.

By the end you can

  • Read the water level on a measuring jug in millilitres
  • Say that 1 000 ml make 1 litre
  • Estimate how many cups fill a 1 litre bottle

A millilitre is a very small amount of water. We write ml for short. A teaspoon holds about 5 ml.

A measuring jug has marks up its side. Look at this jug. It holds up to 500 ml.

Draw it first

Read the water level

  1. A measuring jug that holds 500 ml, with the word "ml" above it. Step 1 shows long marks at 0, 100, 200, 300, 400 and 500, and short marks halfway between them. Step 2 pours in water. Step 3 marks the flat top of the water and labels it "350 ml", at the short mark after 300.0100200300400500ml

    1 The long marks are 100 ml apart. The short marks are halfway, at 50 ml.

  2. A measuring jug that holds 500 ml, with the word "ml" above it. Step 1 shows long marks at 0, 100, 200, 300, 400 and 500, and short marks halfway between them. Step 2 pours in water. Step 3 marks the flat top of the water and labels it "350 ml", at the short mark after 300.0100200300400500ml

    2 Pour in some water. The top of the water is flat.

  3. A measuring jug that holds 500 ml, with the word "ml" above it. Step 1 shows long marks at 0, 100, 200, 300, 400 and 500, and short marks halfway between them. Step 2 pours in water. Step 3 marks the flat top of the water and labels it "350 ml", at the short mark after 300.0100200300400500ml350 ml

    3 The water is at the short mark after 300 ml. It is 350 ml.

Always put your eyes level with the water. Looking from above or below gives a wrong number.

A 500 ml measuring jug with long marks every 100 ml, labelled 0, 100, 200, 300, 400 and 500, and the word "ml" above it. The water stands halfway between the 200 and 300 marks.0100200300400500ml
The water stands halfway between 200 ml and 300 ml.

Worked example

The water is halfway between 200 ml and 300 ml. How much water is there?

  1. The long mark before the water is 200 ml.
  2. The long mark after the water is 300 ml.
  3. Halfway between 200 and 300 is 250. So there is 250 ml.

Answer: 250 ml

A bigger unit is the litre. 1 000 ml make 1 litre. We write L for short.

The most a container can hold is its capacity. A 1 litre bottle has a capacity of 1 000 ml.

See it three ways

With things

Take a small cup that holds 100 ml. Pour 10 of these into one big jug.

As a picture

Ten small boxes in a row, each full of water and holding 100 ml. Under them are the words "10 × 100 ml" and "= 1 000 ml = 1 litre".10 × 100 ml= 1 000 ml = 1 litre

In symbols

10 × 100 ml = 1 000 ml. 1 000 ml = 1 L.

To change litres into ml, use × 1 000. 2 litres is 2 × 1 000 ml.

Two bottles side by side. Each is full of water. Under each bottle are the labels 1 litre and 1 000 ml.1 litre1 000 ml1 litre1 000 ml
Each bottle holds 1 litre, which is 1 000 ml.

Worked example

Change 2 litres into ml.

  1. 1 litre is 1 000 ml.
  2. 2 litres is 2 × 1 000 ml.
  3. 2 × 1 000 = 2 000.

Answer: 2 000 ml

A cup holds about 200 to 250 ml. How many cups fill a 1 litre bottle?

Worked example

A cup holds 250 ml. How many cups fill a 1 litre bottle?

  1. 1 litre is 1 000 ml.
  2. Count on in 250s: 250, 500, 750, 1 000. That is 4 cups.
  3. Check: 1 000 ÷ 250 = 4.

Answer: 4 cups

Four boxes in a row, each labelled 250 ml. Under them is the label 4 cups fill 1 litre.250 ml250 ml250 ml250 ml4 cups fill 1 litre
Four cups of 250 ml fill a 1 litre bottle.

Real cups differ. If your cup holds 200 ml, it takes 5 cups. So this is an estimate. Say 4 or 5 cups.

Try it

How many cups fill a litre?

You need: a bottle marked 1 litre, 1 L or 1 000 ml, one cup, a bowl of clean water, a tray to catch spills.

Be safe: Do not drink the water from this activity. Pour it on a plant after.

  1. Fill the cup to the top. Pour it into the empty bottle.
  2. Make a mark on paper for each cup.
  3. Stop when the water is at the top of the bottle.
  4. Count your marks. Count a part cup as a half.

What you will see: It takes about 4 or 5 cups. A bigger cup needs fewer cups.

If you cannot try it, this is what happens.
Four small boxes of water labelled 1, 2, 3 and 4, with the words "about 4 cups" under them. Beside them is a tall bottle full of water, with the words "1 litre" under it.1234about 4 cups1 litre
On the left, a tall thin glass full of water, labelled "tall thin glass". On the right, a wide bowl with the same water poured in, covering only the bottom, labelled "wide bowl".tall thin glasswide bowl
The glass is poured into the bowl. The water looks low. It is the same water.

A wrong idea many people have

A tall thin glass holds more than a wide bowl.

Why it feels right: Tall things look big. In a thin glass, a little water stands high.

The test that breaks it: Fill a tall thin glass. Pour it into a wide bowl. The water covers only the bottom. The bowl has lots of room, so it holds more.

What is true: Height alone does not tell you how much a container holds. Measure the water in ml to compare.

Key words

millilitre
a very small amount of water. 1 000 ml make 1 litre.
litre
1 000 millilitres. Many water bottles hold 1 litre.
capacity
the most a container can hold.

Back to your guess

The answer is B: Read the mark at the flat top of the water.

Put your eyes level with the water. Read the mark at the flat top of the water. The top mark shows only how much the jug holds.

Check yourself

Try each one before you look. A wrong answer tells you where to go next.

  1. How much water is in the jug?

    A 500 ml measuring jug with long marks every 100 ml, labelled 0, 100, 200, 300, 400 and 500, and the word "ml" above it. The water is between the 100 and 200 marks.0100200300400500ml
    Tap your answer.

    1. Not this one. That is the long mark below the water. The water is past it, at the short mark halfway to 200. Try another.

    2. Yes, that is right. The water is at the short mark halfway between 100 and 200. 100 + 50 = 150.

    3. Not this one. That is the next long mark. The water has not reached it yet. Try another.

    See the answer

    150 ml

    The water is at the short mark halfway between 100 and 200. 100 + 50 = 150.

    • If you chose A: That is the long mark below the water. The water is past it, at the short mark halfway to 200.
    • If you chose C: That is the next long mark. The water has not reached it yet.

  2. How many millilitres are in 3 litres?

    See the answer

    3 000 ml

    1 litre is 1 000 ml. 3 × 1 000 = 3 000.

  3. Mei has a cup that holds 250 ml. How many cups fill a 1 litre bottle?

    See the answer

    4 cups

    1 litre is 1 000 ml. 1 000 ÷ 250 = 4, because 250 + 250 + 250 + 250 = 1 000.

  4. Amina pours a full tall thin glass into a wide pan. The water looks low in the pan. Is there less water now?

    Tap your answer.

    1. Not this one. The water spread out wide, so it stands lower. Nothing was lost. The amount is the same. Try another.

    2. Not this one. It spread out, so it seems like more. Nothing was added. The amount is the same. Try another.

    3. Yes, that is right. Pouring water into a wider container does not change the amount. It only changes how high it stands.

    See the answer

    No. It is the same water.

    Pouring water into a wider container does not change the amount. It only changes how high it stands.

    • If you chose A: The water spread out wide, so it stands lower. Nothing was lost. The amount is the same.
    • If you chose B: It spread out, so it seems like more. Nothing was added. The amount is the same.

  5. A pot holds 4 000 ml of water. How many litres is that?

    See the answer

    4 litres

    1 000 ml make 1 litre. 4 000 ÷ 1 000 = 4.

  6. From an earlier chapter

    A bag of rice weighs 2 kg 500 g. How many grams is that?

    See the answer

    2 500 g

    1 kg is 1 000 g. 2 × 1 000 + 500 = 2 500.

  7. How much water is in the jug?

    A 500 ml measuring jug with long marks every 100 ml, labelled 0, 100, 200, 300, 400 and 500, and the word "ml" above it. The water is between the 400 and 500 marks, at the short mark.0100200300400500ml
    Tap your answer.

    1. Yes, that is right. The water is at the short mark halfway between 400 and 500. 400 + 50 = 450.

    2. Not this one. That is the top mark. It shows what the jug can hold. It is not the water. Try another.

    3. Not this one. That is the long mark below the water. The water is past it, at the short mark. Try another.

    See the answer

    450 ml

    The water is at the short mark halfway between 400 and 500. 400 + 50 = 450.

    • If you chose B: That is the top mark. It shows what the jug can hold. It is not the water.
    • If you chose C: That is the long mark below the water. The water is past it, at the short mark.

  8. Which bottle holds more, 1 litre or 900 ml?

    Tap your answer.

    1. Not this one. You compared 900 with 1. Change to the same unit first. 1 litre is 1 000 ml. Try another.

    2. Yes, that is right. 1 litre is 1 000 ml. 1 000 is more than 900. So the 1 litre bottle holds more.

    3. Not this one. You can compare them. Write both in ml. 1 litre is 1 000 ml. That is more than 900 ml. Try another.

    See the answer

    1 litre

    1 litre is 1 000 ml. 1 000 is more than 900. So the 1 litre bottle holds more.

    • If you chose A: You compared 900 with 1. Change to the same unit first. 1 litre is 1 000 ml.
    • If you chose C: You can compare them. Write both in ml. 1 litre is 1 000 ml. That is more than 900 ml.

  9. Ravi has a cup that holds 100 ml. How many cups fill a 1 litre bottle?

    Tap your answer.

    1. Yes, that is right. 1 litre is 1 000 ml. Count on in 100s: 100, 200, 300 and on to 1 000. That is 10 cups.

    2. Not this one. That is for a 250 ml cup. This cup holds 100 ml, much less. So more cups fill the bottle. Try another.

    3. Not this one. You took the cup size as the count. Count on in 100s: 100, 200, up to 1 000. That is 10 cups. Try another.

    See the answer

    10 cups

    1 litre is 1 000 ml. Count on in 100s: 100, 200, 300 and on to 1 000. That is 10 cups.

    • If you chose B: That is for a 250 ml cup. This cup holds 100 ml, much less. So more cups fill the bottle.
    • If you chose C: You took the cup size as the count. Count on in 100s: 100, 200, up to 1 000. That is 10 cups.

Keep it

Copy this into your exercise book.

Read the mark at the flat top of the water. 1 000 ml make 1 litre. A cup holds about 200 to 250 ml. A litre takes 4 or 5 cups.

Draw: A jug with marks every 100 ml. Draw water up to a mark and write the number.

Reading with a child? A short page for the adult: what this chapter teaches and three questions to ask.

No internet tomorrow? Save the whole book as one file (882 KB). It opens on any phone.