Measuring with informal units: a week of maths
Five days of lessons for Year 1 Measurement. Print this pack and the week is prepared: each day has a one-page plan and a student worksheet, plus cut-out unit strips, 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 unit strips once; they are the same-size units children lay all week.
- Open the free interactive unit on your board. Every plan tells you which picture to show and when.
- 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 muddles children bring, and gives model answers, so you can walk in and teach it.
One day, one lesson
The five lessons fill a week of maths, one lesson of about 40 minutes a day. Run them in order: Day 1 lays units end to end, Days 2 and 3 fix the two rules (no gaps, all the same size), Day 4 shows a bigger unit gives a smaller number, and Day 5 uses one shared unit to compare two things.
The week at a glance
One lesson a day for a week. Each day adds one idea about measuring, so run them in order.
| Day | Lesson | Children learn and do | On screen |
|---|---|---|---|
| 1 | Lay them end to end | Measure a length by laying same-size units end to end and counting | Lay them end to end |
| 2 | The gap trap | See how gaps or overlaps spoil the count; units must touch | The gap trap |
| 3 | Same-size units | Learn that every unit must be the same size, or the count means nothing | Mixed-up units |
| 4 | Big units, small numbers | Measure the same strip in small then big units and watch the number drop | Big units, small numbers |
| 5 | Whose desk is longer? | Measure two things with the same unit and compare the counts | Whose desk is longer? |
How the week builds
In Foundation, children compared two lengths by lining up one end. This week that comparison turns into a count: how many units long? The three rules of a fair count are laid out one at a time (end to end, no gaps, same size), then Day 4 shows that the unit you pick changes the number, and Day 5 uses one shared unit to compare. It opens the way to measuring with a ruler in Year 2, where the units become centimetres.
Materials for the week (one trip)
- From the classroom: scissors, pencils, this pack printed.
- Sets of same-size units to lay end to end: connecting cubes, wooden blocks and paperclips work well. Keep each set to one size, so a count stays fair.
- The printed unit strips in this pack (cut-out sheet 1), for children without a set of cubes to hand.
- A few everyday objects to measure: a pencil, a shoe, a book, a desk. No special equipment to buy.
Dear families
This week in maths, Year 1 measures how long things are without a ruler. We lay same-size units end to end, count them, and learn the rules that keep a count fair: no gaps, no overlaps, and every unit the same size.
Try this at home
- Measure a spoon or a book with same-size blocks laid end to end. How many blocks long is it?
- Use pieces of dry pasta as your units. Lay them touching, with no gaps, and count.
- Measure the hallway in footsteps, heel to toe. Count your steps, then count a grown-up’s.
- Measure the same thing in big steps and little steps. Which gives the smaller number, and why?
My measuring this week
Fill one row a day. Tick when you laid same-size units end to end and counted them.
| Day | What I measured | I used same units | How many units |
|---|---|---|---|
| Monday | □ | ||
| Tuesday | □ | ||
| Wednesday | □ | ||
| Thursday | □ | ||
| Friday | □ |
Printed from the free seegongsik measurement teaching pack · seegongsik.com/au/y1/measurement/AC9M1M02/pack
Lay them end to end
In Foundation, children compared two lengths by lining up one end. Today that comparison becomes a count. We lay same-size units, one after another, touching end to end, and count how many make the length. Laying them end to end is the whole idea.
We are learning to
- lay same-size units end to end along an object,
- start at the very end and leave no gaps,
- count the units to say how long the object is.
Success criteria
- I can lay units end to end from one end.
- I can count them and say how many units long it is.
You need
Sets of same-size units to lay: connecting cubes, wooden blocks or paperclips, one set per pair. A few objects to measure (a pencil, a shoe, a book). The printed unit strips (cut-out sheet 1) for anyone without cubes. The worksheet, one per child.
Lesson flow (about 40 minutes)
| 10 min | How many blocks long? Hold a pencil beside a line of cubes. Start the first cube at the very tip of the pencil, then add another, touching. Ask: “Where does the first block go? How do we make sure we count fairly?” |
| 20 min | Lay and count Pairs measure the objects on the worksheet, laying units from one end, touching, no gaps, then counting. Ask: “Read them aloud with me: one, two, three. Each block touches the last one.” |
| 10 min | Say how many Children write the count for each object and check a neighbour started at the end. Ask: “How long is your pencil? Did your blocks all touch, with no gaps?” |
Two short bursts instead? End the first burst after laying and counting the pencil. Start the second by measuring a longer object, like a shoe, and counting on from there.
Watch for these ideas
- Starting the first unit part way along, not at the very end, so the count comes out wrong.
- Counting the gaps between units, or the lines, instead of the units themselves.
- Thinking bigger, brighter objects need bigger numbers no matter the unit.
Answers
- Pencil = 6 cubes, marker = 4 cubes, glue stick = 5 cubes. The unit boxes are printed under each object, so a correct count matches the boxes.
- A fair count starts at the very end, with units touching end to end and no gaps.
- Draw-your-own varies: check the units are the same size and drawn touching.
Lay them end to end
Each object has unit boxes under it. Count the boxes from one end to the other. Then write how many cubes long it is.
Measure your own
Find a real object. Lay same-size cubes end to end along it and count. Then draw your cubes.
My object is ______ cubes long.
The gap trap
A count is only fair when the units touch. Today children meet the trap: leave gaps and the count comes out too small, overlap the units and it comes out too big. The rule is simple, end to end, no gaps, no overlaps.
We are learning to
- lay units so they touch, with no gaps and no overlaps,
- spot a measurement that used gaps or overlaps,
- say why gaps make the count too small and overlaps make it too big.
Success criteria
- I can tell a fair measurement from one with gaps.
- I can give the true count and say why the other is wrong.
You need
Same-size units (cubes or blocks). A ribbon or strip of paper to measure. The worksheet, one per child. It helps to have one child lay units with gaps on purpose, so the class can see the trap.
Lesson flow (about 40 minutes)
| 10 min | Two counts, one ribbon Measure a ribbon fairly and get 8. Then measure it again with gaps and get only 6. Ask: “Same ribbon, same blocks. Why did the number change? Where did the length go?” |
| 20 min | Spot the fair one Children look at the two measurements on the worksheet, circle the fair one and write the true count. Then they lay their own units to check. Ask: “Which row has no gaps? That is the fair count. What is the true number?” |
| 10 min | Say the rule Children finish the sentence: units must touch because. Overlaps get a mention too. Ask: “Gaps make the count too small. What do overlaps do to the count?” |
Two short bursts instead? End the first burst after spotting the fair one. Start the second by making an overlap on purpose and counting the units twice.
Watch for these ideas
- Leaving small gaps between units and still trusting the count.
- Overlapping units so the same bit of length is counted twice.
- Thinking any row of blocks gives the right answer, however it is laid.
Answers
- Row A (units touching) is the fair measurement. The ribbon is 8 cubes long.
- Row B has gaps, so only 6 units fit; gaps make the count too small.
- Units must touch because gaps leave length uncounted and overlaps count length twice.
The gap trap
Two children measured the same ribbon with the same cubes. Circle the one who measured fairly. Then write the true length.
Cubes touch, end to end.
Cubes have gaps between them.
The fair measurement
The fair one is Row ______. The ribbon is ______ cubes long.
Say how you know
Gaps make the count wrong because ____________________
Same-size units
Yesterday the rule was: no gaps. Today it is the other half: every unit must be the same size. Mix a big block with a small one and the count still gives a number, but it no longer means a length. Six of what, exactly?
We are learning to
- measure using units that are all the same size,
- see why mixing big and small units breaks the count,
- say that a count only means a length when the units are uniform.
Success criteria
- I can choose units that are all the same size.
- I can say why a count with mixed units means nothing.
You need
A set of same-size units and a few odd ones of a different size (a big block among the small cubes). A book or strip to measure. The worksheet, one per child.
Lesson flow (about 40 minutes)
| 10 min | Six of what? Measure a book with 8 equal cubes. Then measure it again with big and small blocks mixed and get 6. Ask: “Both times we got a number. But six of what? Can we trust it?” |
| 20 min | Sort and measure Children pick a set of same-size units, measure the book on the worksheet and write the uniform count. Then they look at the mixed row and say why it fails. Ask: “What did you do first to make your count fair? Why toss out the odd-size block?” |
| 10 min | Say the rule Children finish: units must all be the same size because. Ask: “If my friend used bigger cubes than you, could we compare our counts?” |
Two short bursts instead? End the first burst after measuring with same-size cubes. Start the second by comparing two children who used different-size cubes.
Watch for these ideas
- Mixing a big block in with small ones and still reading off the count.
- Thinking any objects can be units, even when they are different sizes.
- Comparing two counts taken with different-size units as if they matched.
Answers
- Row A (all the same size) is the fair measurement. The book is 8 cubes long.
- Row B mixes big and small units, so its count of 6 does not tell a length.
- Units must be the same size because only then does each one add the same amount to the count.
Same-size units
The same book was measured two ways. Circle the row that used same-size units. Then write how long the book is.
All the units are the same size.
Big and small units are mixed together.
The fair measurement
The fair one is Row ______. The book is ______ cubes long.
Say how you know
Units must all be the same size because ____________________
Big units, small numbers
Here is the surprise of the week: measure the same strip with a bigger unit and the number gets smaller. Fewer big steps fit than small steps. So a bigger number does not always mean a longer thing, it depends on the unit.
We are learning to
- measure the same length with a small unit, then a big one,
- notice the count goes down when the unit gets bigger,
- say that a bigger number does not always mean a longer thing.
Success criteria
- I can measure one strip in small units and in big units.
- I can say which unit gives the smaller number and why.
You need
Two sizes of unit, where the big one is about twice the small one (small cubes and long blocks, or paperclips and lolly sticks). A strip of card to measure. The worksheet, one per child.
Lesson flow (about 40 minutes)
| 10 min | Same strip, two units Measure a strip with small cubes: 8. Then measure the very same strip with big blocks: 4. Ask: “The strip did not change. Why did the number get smaller?” |
| 20 min | Count both ways Children measure the strip on the worksheet in small units, then big units, and write both counts. Ask: “Which unit needed more of them to cover the strip? Which gave the bigger number?” |
| 10 min | Bigger number, longer? Children decide if a bigger number always means a longer thing, and give a reason. Ask: “Ten paperclips or three blocks. Which is longer? What must you ask first?” |
Two short bursts instead? End the first burst after counting in small units. Start the second by counting the same strip in big units and comparing.
Watch for these ideas
- Thinking the bigger number always means the longer thing, without asking about the unit.
- Expecting the count to stay the same when the unit changes.
- Guessing that a bigger unit needs a bigger number, not a smaller one.
Answers
- Small units: 8. Big units: 4. The same strip, so 8 small = 4 big.
- The big unit gives the smaller number, because each big unit covers more of the strip, so fewer are needed.
- A bigger number does not always mean longer: you must know the size of the unit first.
Big units, small numbers
Here is one strip, measured two ways. Count the small units, then the big units. Write both counts.
The strip is ______ small units long.
The same strip is ______ big units long.
What changed?
The ______ unit gives the smaller number.
A bigger number does not always mean longer because ____________________
Whose desk is longer?
The week comes together today. To compare two things fairly, measure them both with the same unit, then compare the counts. If the units differ, the numbers cannot be trusted. The bigger count is longer, and the difference tells you by how many units.
We are learning to
- measure two objects with the same unit,
- compare the counts to say which is longer,
- say by how many units longer, using the difference.
Success criteria
- I can measure two things with the same unit.
- I can say which is longer and by how many units.
You need
One set of same-size units for the whole comparison (do not mix sizes). Two objects to compare, like two desks or two ribbons. The worksheet, one per child. The mini-check to hand out at the end.
Lesson flow (about 40 minutes)
| 10 min | Same unit for both Measure two desks, first with different hands, then with the same blocks. Ask: “Different hands gave a muddle. Why does one shared unit let us compare fairly?” |
| 20 min | Measure, compare, subtract Pairs measure two ribbons on the worksheet in the same cubes, say which is longer, and work out by how many. Then the mini-check. Ask: “Ben’s is 12, Ava’s is 9. Which is longer? How many more cubes is that?” |
| 10 min | Mini-check Hand out the mini-check at the back of the pack. Children work on their own; read each question aloud for those who need it. |
Two short bursts instead? End the first burst after measuring and comparing the two ribbons. Start the second with the mini-check on its own.
Watch for these ideas
- Comparing two counts that were taken with different-size units, as if the numbers matched.
- Saying which is longer but not working out by how many.
- Forgetting to lay units end to end, with no gaps, on the second object too.
Answers
- Ava’s ribbon = 9 cubes, Ben’s ribbon = 12 cubes.
- Ben’s is longer. It is 12 - 9 = 3 cubes longer.
- Measure-your-own varies: check both objects were measured with the same unit, and the difference matches the two counts.
Whose is longer?
Both ribbons were measured with the same cubes. Count each one. Then say which is longer and by how many cubes.
Compare
______’s ribbon is longer. It is ______ cubes longer than the other one.
Measure your own
Find two things in the room. Measure both with the same cubes. Draw them and count.
The ______ is longer by ______ cubes.
Same-size unit strips
Cut along the dashed lines to make a set of same-size units. Keep each strip in its own pile, so every unit in a pile is the same size. Lay them end to end, touching, with no gaps, to measure. Use them all week.
Cube units
Paperclip units
Teacher note: the cube units are all one size and the paperclip units are all another. Do not mix the two piles in one measurement, or the count stops meaning a length (Day 3).
Things to measure
Measure each object with your cube units. Lay them from one end, touching, with no gaps, then count. Write how many cubes long it is.
Teacher note (cube counts): crayon = 3, pencil = 6, book = 8, shoe = 9. Each object is printed exactly that many cube units long, so a fair measurement matches. The cube strip on sheet 1 is the matching unit.
What we know: measuring with informal units
Work on your own. Your teacher can read the questions to you. Say how you know when you can.
- Count the cubes. How many cubes long is this pencil?a pencilIt is ______ cubes long.
- Which measurement is right: the one with gaps between the units, or the one laid end to end with no gaps? Circle it.
- Why must all the units be the same size? ____________________
- You measure one strip with big blocks and with small cubes. Which unit gives the smaller number, the big one or the small one? Circle it.
- These two ribbons were measured with the same cubes. Which is longer, and by how many cubes?Ribbon 1Ribbon 2Ribbon ______ is longer, by ______ cubes.
Answers and marking guide
Answers
- 7 cubes (the seven printed units, end to end).
- The one laid end to end, with no gaps.
- So each unit adds the same amount, and the count means a real length. Mixed sizes make the count meaningless.
- The big unit gives the smaller number (fewer big units fit the same strip).
- Ribbon 2 is longer, by 3 cubes (9 - 6 = 3).
A quick three-level guide
| Idea | Working towards | At standard | Beyond |
|---|---|---|---|
| End to end (Q1) | guesses a number | lays units end to end and counts | starts at the very end and checks the last unit |
| No gaps (Q2) | trusts any row of units | picks the row laid end to end | explains gaps make the count too small |
| Same size (Q3) | mixes unit sizes | measures with same-size units | explains why uniform units let a count mean a length |
| Unit and number (Q4) | thinks bigger unit gives a bigger number | knows the bigger unit gives the smaller number | explains fewer big units fit the same length |
| Compare (Q5) | compares counts from different units | measures both with one unit and compares | gives the difference: longer by how many units |
Five questions, five ideas. A child at standard lays same-size units end to end, counts them, and compares two things with one unit.
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 | End to end | No gaps | Same size | Big unit, small number | Compare two things |
|---|---|---|---|---|---|
The five columns are the five days: lay units end to end, no gaps, same-size units, a bigger unit gives a smaller number, and comparing two things with one unit.