Choosing Metric Units: a week of ready-to-teach maths
Five days of lessons for Year 5 Measurement. Print this pack and the week is prepared: each day has a one-page plan and a student worksheet, plus eight unit mats with sixteen things to measure, twenty-four same-measure cards, a mini-check and every answer.
Start here: five minutes to Monday
- Skim the week at a glance on the next page.
- Print the five days. Each day is two A4 sheets: a plan and a worksheet.
- Cut out the things-to-measure cards and the same-measure cards once, and keep each set in an envelope.
- Open the free interactive unit on your board. Every plan tells you which picture to show and which buttons to press.
- Teach straight from the plan. Timings, talk prompts, misconceptions and answers are all on the one page.
No maths background needed
This pack is written for the busy generalist teacher. Each plan explains the idea in plain words, lists the misconceptions children bring, and gives the answers. The big idea of the week: a unit is chosen to suit the size of the thing, so the number is sensible, and every metric unit is linked to its neighbours by 10, 100 or 1000. A smaller unit, such as millimetres instead of centimetres, rounds away less, so it gives a more accurate measure, and a combination such as 1 m 25 cm keeps a big unit for the bulk and a small one for the rest.
One day, one lesson
The five lessons fill a week of maths, one lesson of about 50 minutes a day. Run them in order: each day stands on the one before. Every plan marks a split point if your timetable runs two shorter sessions.
The week at a glance
One lesson a day for a week. Each day stands on the day before, so run them in order.
| Day | Lesson | Children learn and do | On screen |
|---|---|---|---|
| 1 | Which unit fits? | Sort things to measure onto unit mats, and choose the unit that gives a sensible number | Match the unit to the thing |
| 2 | The metric ladder | Write one length in millimetres, centimetres, metres and kilometres, and order lengths in mixed units | The metric ladder for length |
| 3 | Mass and capacity | Read jugs and scales between the marks, and change grams to kilograms and millilitres to litres | Units for mass and capacity |
| 4 | A finer measure | Measure to the nearest centimetre and to the nearest millimetre, and say which is more accurate | A smaller unit gives a finer measure |
| 5 | Combine units | Write measures across two units and back, compare them, and play same-measure pairs; play the unit quiz | Combining units for precision |
How the week builds
Day 1 chooses units; Days 2 and 3 link the units of length, mass and capacity by 10, 100 and 1000; Day 4 measures more accurately with a smaller unit; and Day 5 combines units. It builds on Year 4’s reading of scales with unmarked and partial units (AC9M4M01), and it leads straight into perimeter and area in metric units (AC9M5M02), and in Year 6 to converting between units with decimals (AC9M6M01).
Materials for the week (one trip)
- From the classroom: 30 cm rulers with millimetres, a metre ruler or tape measure, kitchen scales, a 1 L measuring jug, water, scissors, envelopes, this pack printed.
- Cut out once: the sixteen things-to-measure cards (Day 1) and the twenty-four same-measure cards (Day 5); keep the eight unit mats whole.
Words for the word wall
millimetre, centimetre, metre, kilometre, gram, kilogram, millilitre, litre, mass, capacity, accurate, scale
Dear families
This week in maths, Year 5 chooses metric units: centimetres for a pencil, kilograms for a suitcase, litres for a bucket. Every unit is linked to its neighbours by 10, 100 or 1000, so 1 m is 100 cm, 1 kg is 1000 g and 1 L is 1000 mL, and a measure such as 1 m 25 cm is the same as 125 cm.
Try this at home
- Read the labels in the pantry together. Which are in grams, kilograms, millilitres or litres?
- Ask: would you measure a fridge in centimetres or kilometres? Why?
- Measure a hand span to the nearest centimetre, then to the nearest millimetre.
- Ask: is 1 L 500 mL the same as 1500 mL? How do you know?
Measures I found this week
Fill one row a day. Write something you found, its measure and its unit.
| Day | What I found | Its measure |
|---|---|---|
| Monday | ||
| Tuesday | ||
| Wednesday | ||
| Thursday | ||
| Friday |
Printed from the free seegongsik Choosing Metric Units teaching pack · seegongsik.com/au/y5/measurement/AC9M5M01/pack
Which unit fits?
A measure is a number and a unit, and the unit is chosen to suit the size of the thing. A classroom about 9 m long is 9000 mm, 900 cm, 9 m, 0.009 km: every one is true, but metres give the simplest number to say and use. First the kind of unit (length, mass or capacity), then the size.
We are learning to
- choose a unit of the right kind: length, mass or capacity,
- choose a unit of the right size, so the number is sensible,
- estimate a measure before checking it.
Success criteria
- I can choose the unit for a thing and say why the others do not fit.
- I can estimate a measure in the unit I chose.
You need
The unit mats and cards (cut-out sheet 1), one set per group. A metre ruler, kitchen scales and a 1 L jug to pass around. The worksheet, one per child.
Lesson flow (about 50 minutes)
| 10 min | Match the unit Show the board (see the box). Children hold up 1, 2 or 3 fingers for a button before anyone presses. Ask: “Millimetres would work for a pencil too. Why is centimetres the better choice?” |
| 30 min | Sort the cards Model the classroom length in each unit (above) and choose metres together. Groups sort the cards onto the mats, then do Parts A and B. Ask: “Which card was hardest to place? What made you choose?” |
| 10 min | Estimate first Children do Part C, passing round the metre ruler, scales and jug. Ask: “Was your estimate close? Did the unit you chose help?” |
Two half-sessions instead? Split after the sort; start Session B with Part B.
Watch for these ideas
- Choosing a unit of the wrong kind, such as grams for the water in a bucket. Mass and capacity answer different questions.
- Choosing the biggest or the smallest unit every time. Ask what the number would be.
- Thinking only one unit is right. Several are true; the best one gives a sensible number.
Answers
- Part A: mm: D and I; cm: G and M; m: A and L; km: E and N; g: F and O; kg: C and J; mL: B and K; L: H and P.
- Part B: m, kg, L, mm, g, km. Part C: estimates vary; sensible units are centimetres (or metres) for the desk, grams for the book and millilitres for the mug.
Which unit fits?
A. Sort the cards onto the unit mats. Write the card letters.
| Unit | Cards | Unit | Cards |
|---|---|---|---|
| mm | g | ||
| cm | kg | ||
| m | mL | ||
| km | L |
B. Circle the best unit
C. Estimate first, then measure
| Thing | Unit I chose | My estimate | Measured |
|---|---|---|---|
| the length of your desk | |||
| the mass of your reading book | |||
| the water a mug holds |
The metric ladder
The units of length form a ladder: 10 mm make 1 cm, 100 cm make 1 m and 1000 m make 1 km. A bookshelf 1.8 m tall is 180 cm and 1800 mm. Stepping down to a smaller unit multiplies the number and stepping up divides it, while the length itself never changes.
We are learning to
- write one length in millimetres, centimetres, metres and kilometres,
- explain why a smaller unit gives a bigger number,
- compare lengths written in different units.
Success criteria
- I can write a length in mm, cm and m.
- I can order lengths written in different units.
You need
A metre ruler. Mini whiteboards. The worksheet, one per child.
Lesson flow (about 50 minutes)
| 10 min | One desk, four units Show the board (see the box). Children predict each number before it is pressed. Ask: “The desk did not change. Why did the number change?” |
| 30 min | Up and down the ladder Model the bookshelf against the metre ruler: 1.8 m, 180 cm, 1800 mm. Children do Parts A and B. Ask: “From metres to centimetres, do you multiply or divide? By what?” |
| 10 min | Shortest to longest Children do Part C. Ask: “How can you compare a length in metres with one in millimetres?” |
Two half-sessions instead? Split after Part A; start Session B with the bookshelf again.
Watch for these ideas
- Moving the wrong way, as in 2 m = 0.02 cm. A smaller unit needs more of them, so the number grows.
- Using 10 for every step, as in 1 m = 10 cm. Only millimetres to centimetres is 10.
- Comparing the numbers without the units: thinking 90 cm is longer than 1.2 m because 90 is bigger than 1.2.
Answers
- Part A: 2500 mm = 250 cm = 2.5 m; 450 mm = 45 cm = 0.45 m; 3000 mm = 300 cm = 3 m; 70 mm = 7 cm = 0.07 m; 1250 mm = 125 cm = 1.25 m; 85 mm = 8.5 cm = 0.085 m.
- Part B: 5 km = 5000 m; 2.4 km = 2400 m; 750 m = 0.75 km; 3200 m = 3.2 km. Part C: 0.0012 km, 140 cm, 1.5 m, 1600 mm.
The metric ladder
A. Fill the gaps: the same length in each unit
| mm | cm | m |
|---|---|---|
| 2.5 m | ||
| 45 cm | ||
| 3000 mm | ||
| 7 cm | ||
| 1.25 m | ||
| 85 mm |
B. Kilometres and metres
C. Order from shortest to longest
How did you compare them?
Mass and capacity
Mass and capacity climb a ladder too, in one step of 1000: 1000 g make 1 kg and 1000 mL make 1 L. A 1.5 kg bag of flour is 1500 g, and a 600 mL bottle is 0.6 L. Jugs and scales label only some marks, so children work out what each mark is worth before they read between the labels.
We are learning to
- read a jug or a scale between its labelled marks,
- change grams to kilograms and millilitres to litres, and back,
- choose grams or kilograms, millilitres or litres, for a thing.
Success criteria
- I can read a jug or a scale to the nearest mark.
- I can write a mass in grams and in kilograms.
You need
Kitchen scales, a 1 L jug, water and a few labelled packets (flour, rice, a juice bottle). The worksheet, one per child.
Lesson flow (about 50 minutes)
| 10 min | Units for each quantity Show the board (see the box). Children name the units before each reveal. Ask: “Length has four units here and mass has two. What links grams to kilograms?” |
| 30 min | Read between the marks Model with the class jug: pour water to an unlabelled mark and work out what it is worth, then weigh a packet and read the scales. Children do Parts A and B. Ask: “The marks go up in hundreds but only some have numbers. What is this mark worth?” |
| 10 min | Choose the unit Children do Part C. Ask: “Could you give a cat’s mass in grams? Why do we choose kilograms?” |
Two half-sessions instead? Split after the jugs; start Session B by weighing a packet.
Watch for these ideas
- Reading the nearest labelled number instead of the mark: a level one mark above 200 mL read as 200 mL.
- Treating 1 kg as 100 g, like metres and centimetres. Mass and capacity step by 1000.
- Mixing mass and capacity, such as giving the water in a jug in grams.
Answers
- Part A: jugs 300 mL = 0.3 L, 700 mL = 0.7 L, 900 mL = 0.9 L; scales 700 g = 0.7 kg, 1300 g = 1.3 kg, 1900 g = 1.9 kg.
- Part B: 2 kg = 2000 g; 3500 g = 3.5 kg; 4 L = 4000 mL; 250 mL = 0.25 L. Part C: L, mL, kg, g; estimates vary.
Mass and capacity
A. Read each jug and each scale
B. Change the unit
C. Choose the unit, then estimate
| Thing | Unit | My estimate |
|---|---|---|
| the water in a full bucket | ||
| the milk in a mug | ||
| the mass of a cat | ||
| the mass of a slice of cheese |
A finer measure
A smaller unit rounds away less. A glue stick 96 mm long is 10 cm to the nearest centimetre, which hides 4 mm; to the nearest millimetre it is 96 mm. Children measure with the millimetre marks and say which measure is more accurate, and when the extra accuracy matters.
We are learning to
- measure a length to the nearest centimetre and to the nearest millimetre,
- explain why the smaller unit gives a more accurate measure,
- decide how accurate a measure needs to be.
Success criteria
- I can measure a length to the nearest millimetre.
- I can say which of two measures is more accurate, and why.
You need
A 30 cm ruler with millimetres, one per child. A glue stick to model with. The worksheet, one per child.
Lesson flow (about 50 minutes)
| 10 min | Measure finely Show the board (see the box). Children estimate each length in millimetres before it is pressed. Ask: “84 mm and 8 cm describe the same crayon. Which tells us more?” |
| 30 min | Nearest cm, nearest mm Model the glue stick on a ruler: one end on zero, read the centimetres, then count on the millimetres. Children do Parts A and B. Ask: “Where must the end of the object sit on the ruler? Why?” |
| 10 min | Which is more accurate? Children do Part C. Ask: “When is ‘about 30 cm’ good enough? When would you need the millimetres?” |
Two half-sessions instead? Split after Part A; start Session B by measuring the glue stick again.
Watch for these ideas
- Starting from the end of the ruler instead of zero. Many rulers have a gap before the 0.
- Writing 13 cm and 6 mm as 13.6 mm or 136 cm. Ten millimetres make one centimetre.
- Rounding down every time: 67 mm to the nearest centimetre written as 6 cm. It is nearer 7 cm.
Answers
- Part A: a pencil 14 cm, 136 mm; a feather 9 cm, 87 mm; an eraser 4 cm, 43 mm; a leaf 12 cm, 118 mm.
- Part B: answers vary; check that each nearest-centimetre measure is the nearest-millimetre one rounded. Part C: Bea’s 297 mm is more accurate; ‘about 30 cm’ rounds away 3 mm.
A finer measure
A. Read each length to the nearest cm and to the nearest mm
B. Measure these yourself
| Thing | Nearest cm | Nearest mm |
|---|---|---|
| your pencil | ||
| your eraser | ||
| your thumb | ||
| a whiteboard marker |
C. Which is more accurate?
Ali measured a sheet of A4 paper as ‘about 30 cm’. Bea measured it as ‘297 mm’. Whose measure is more accurate? Explain.
Combine units
A combination keeps a big unit for the bulk of a measure and a small one for the rest: a child 142 cm tall is 1 m 42 cm. Children write measures both ways and watch the zeros: 2 kg 30 g is 2030 g, because each kilogram is 1000 g.
We are learning to
- write a measure across a big and a small unit,
- write a combined measure in the smaller unit,
- compare measures written in different ways.
Success criteria
- I can write a measure in two units and back again.
- I can say which of two measures is more when they are written differently.
You need
The same-measure cards (cut-out sheet 2), one set per group of three or four. The worksheet, one per child.
Lesson flow (about 50 minutes)
| 10 min | Combine units Show the board (see the box). Children write the combined measure before it is pressed. Ask: “1250 mm became 1 m 25 cm. Why is there no 250 in it?” |
| 30 min | Both ways Model 142 cm = 1 m 42 cm and 2 kg 30 g = 2030 g. Groups play same-measure pairs for ten minutes, then children do Parts A and B. Ask: “3050 g and 3 kg 500 g look alike. Are they a pair?” |
| 10 min | Quiz game Run the unit’s self-check quiz as a class game: pairs agree on an answer before it is pressed. Early finishers do Part C. |
Two half-sessions instead? Split after the pairs game; start Session B with Part A.
Watch for these ideas
- Dropping a zero: 3 m 8 cm written as 38 cm. Each metre is 100 cm, so it is 308 cm.
- Splitting at the wrong place: 1750 mL as 17 L 50 mL. A litre is 1000 mL, so split off the thousands.
- Comparing the first numbers only: 1 kg 90 g against 1500 g. Write both in grams first.
Answers
- Part A: 175 cm = 1 m 75 cm; 2650 g = 2 kg 650 g; 3200 mL = 3 L 200 mL; 1080 m = 1 km 80 m; 406 cm = 4 m 6 cm; 5005 g = 5 kg 5 g.
- Part B: 2 m 40 cm = 240 cm; 1 kg 75 g = 1075 g; 4 L 300 mL = 4300 mL; 3 km 600 m = 3600 m. Part C: 2800 g is heavier, since 2 kg 80 g = 2080 g; 190 cm is longer, since 1 m 9 cm = 109 cm.
Combine units
A. Write each measure in two units
B. Write each measure in one unit
C. Which is more?
Which is heavier: 2 kg 80 g or 2800 g? How do you know?
Which is longer: 1 m 9 cm or 190 cm? How do you know?
Unit mats and things to measure
Keep the eight mats whole and cut out the sixteen cards (Day 1), one set per group. Put each card on the unit that gives a sensible number for it.
Teacher note: two cards belong on each mat. The sort is on the Day 1 plan.
Same-measure pairs
Cut out the twenty-four cards (Day 5), one set per group of three or four. Shuffle them face down. Take turns to turn over two cards; keep them if they show the same measure.
Teacher note: twelve pairs, with two near misses to catch: 3050 g and 3500 g, and 205 cm and 250 cm.
What we know: Choosing Metric Units
Work on your own. Show your thinking if you can.
- Circle the best unit for the mass of a school bag: g kg L
- Circle the best unit for the length of a car: m mm km
- 3.4 m = __________ cm
- 2500 g = __________ kg
- How much water is in the jug? __________ mL
- A pencil was measured as ‘about 15 cm’ and as ‘148 mm’. Which measure is more accurate? Why?
- Write 1450 mL in litres and millilitres. ______ L ______ mL
- Write 3 m 7 cm in centimetres. __________ cm
How did this week feel? Circle one: I can teach it · I am getting there · I need more help
Answers and marking guide
Answers
- kg
- m
- 340 cm
- 2.5 kg
- 500 mL
- 148 mm: a millimetre is smaller, so it rounds away less; ‘about 15 cm’ hides 2 mm
- 1 L 450 mL
- 307 cm
A quick three-level guide
| Idea | Working towards | At standard | Beyond |
|---|---|---|---|
| Choosing units (Q1, Q2) | picks a unit of the wrong kind or size | picks the unit that gives a sensible number | explains why the other units are too big or too small |
| Converting (Q3, Q4) | moves the wrong way, or uses 10 for every step | multiplies or divides by 10, 100 or 1000 | explains why the number grows or shrinks |
| Reading and accuracy (Q5, Q6) | reads only the labelled marks | reads between the marks and chooses the finer measure | explains how much each unit rounds away |
| Combining units (Q7, Q8) | drops a zero, as in 3 m 7 cm = 37 cm | writes measures in one unit and in two | compares measures written in different ways |
Eight questions, four ideas. A child at standard answers most questions and can say why, by naming the unit, the step of 10, 100 or 1000, or how much a unit rounds away.
Weekly class record
Jot a tick as you move around the room; the mini-check fills any gaps. A tick a day is plenty.
| Name | Chooses a unit | Climbs the ladder | Reads scales | Measures finely | Combines units |
|---|---|---|---|---|---|
The five columns are the five days: choosing a unit, climbing the metric ladder, reading scales, measuring finely, and combining units.