Year 2 Teaching Sequence autumn M1 – Length (four days)
Prerequisites:
 Estimate, measure and compare objects, choosing and using suitable uniform non-standard or standard units (see Year
1 teaching sequence M1)
 Recite numbers to 100 (see teaching sequence 1 and oral and mental starter bank M1)
 Order numbers to 100, compare two numbers, say which is more or less (see teaching sequence 1 and oral and mental
starter bank M1)
 Say a number between any given neighbouring pairs of multiples of ten (e.g. 40 and 50) (see teaching sequence 1 and
oral and mental starter bank M1)
Overview of progression:
Children recognise that we measure distances (lengths and heights) by repeating a unit. They also realise that the unit must
be uniform. Chn are introduced to standard units – metres and centimetres. They measure objects to the nearest 10
centimetres (decimetre) and then to the nearest centimetre. They estimate the lengths of items by choosing a range. They
use string to measure curved lines. They choose which pieces of measuring equipment and units (centimetres, decimetres or
metres) are best for measuring different distances.
Note that it can be helpful to have a purposeful context for measurement, for example measuring wood for a model in D&T,
or jumps and throws in PE. Try to build in these cross-curricular links if possible.
Note that it is important that children have some ‘benchmarks’ such as a decimetre, a 30cm ruler and a metre stick to help
them to estimate distances, particularly until they have more experience of measuring.
Watch out for children who forget that a centimetre and a metre are units and see them only as marks on a ruler.
Watch out for children whose counting and ordering skills are insecure making measuring difficult. Try to ensure that the
items they measure are not longer than the number they can count up to with confidence.
© Original teaching sequence copyright Hamilton Trust, who give permission for it to be adapted as wished by individual users.
Y2 Maths TS_M1 – Aut – 4days
Objectives:
 Estimate, measure and compare lengths, choosing and using suitable standard units and suitable measuring instruments
Whole class
Group activities
Paired/indiv practice
Resources
Show children some wax crayons – you need
some which are of varying lengths. Choose a
child, and ask him or her to hold one arm out
straight. We are going to measure the length
of Sam’s arm in crayons. Choose short crayons
and measure Sam’s arm. Write how many
crayons. Then repeat this selecting all the
longer crayons. Write how many. Ask children
why we got two different answers? Had Sam’s
arm shrunk?! No! The first lot of crayons
were shorter and so more fitted along Sam’s
arm. Discuss how this means we need to use
something that is ALWAYS the same length to
measure with. Show children the decimetre
rods. These rods are all the same length. They
do not vary. Measure Sam’s arm using the rods.
Record the length. Sam’s arm is 5 rods long.
Discuss what happens if it is not exact – we
could say that it is five and half rods.
Choose a child to lie on a table in front of the
class. How long is Annie? Discuss how we might
measure her length. Pass round some 1cm
cubes. Show chn a decimetre strip (see
resources). This is a decimetre; it is ten
centimetres. Pass round several strips.
Decimetres or ten centimetres are useful
units for measuring things. How many
decimetres long is Annie? Encourage chn to
Groups of 5/6 children
Lay out some decimetre rods along the
table. Give children a pile of pieces of
string. Each child also needs a
whiteboard and pen. Children have to
choose one piece of string and spread it
out. In turn, go round the group and ask
each child to estimate how many rods
will fit along their string. They each
write their estimate on their
whiteboard. Then allow each child in the
group to measure their string using one
rod, and laying it repeatedly all along
the string. They must make sure that
they do not overlap it or leave gaps so
that they get an accurate
measurement. Each child writes the
length of their string – how close were
their estimates?
Several groups of 2 or 3
Help several groups of 2 or 3 children
to measure each other in decimetres.
One child lies on the floor and the
others lay decimetres (cardboard
strips or rods) along her length. They
must make sure that the decimetre
strips or rods do not overlap and also
that there are not big gaps between
Chn work in pairs. They put a strip
of paper round their head like a
crown. They tear off the strip so
it will be the right length. Before
they stick the ends together with
sellotape, they use a decimetre
rod to measure the length of
their crown. They write the
length of their crown in rods on
the crown alongside their own
name.
 Wax crayons
of varying
lengths
 Decimetre rods
(Dienes,
Cuisenaire or
colour factor)
 Whiteboards
and pens
 Strips of paper
 Scissors
 Sellotape
 Pens
Chn make their own decimetre
strip with their name on it. See
resources for a template. The
strips need to be made of card so
that they are fairly robust.
Children can then measure the
length of their tray in
decimetres. How long is the tray?
How wide is it? Encourage them
 Centicubes or
any 1cm cubes
 Decimetre
strips (made of
card).
 Decimetre rods
(Dienes,
Cuisenaire or
colour factor)
© Original teaching sequence copyright Hamilton Trust, who give permission for it to be adapted as wished by individual users.
Y2 Maths TS_M1 – Aut – 4days
estimate. Write some of their guesses on the
board. Collect up the decimetre strips and
point out that they are all exactly the same
length. Lay decimetre strips along the length
of Annie and work out how long she is. Discuss
what happens if she is not an exact number –
some children will understand the concept of a
half. Record her length in decimetres: Annie is
13 decimetres long.
Ask children to show their decimetre strips.
Discuss the fact that these are all the same
length. Point out that each one is divided into
ten. This is because it is ten centimetres long.
Tell children to put their finger on one space
on the decimetre. It is one finger wide. One
centimetre is one finger wide. A centimetre is
a very small unit and is useful for measuring
smaller things. A centimetre is used to
measure things by people all over the world. It
is always the same!
Draw round your foot on paper, and hold it up.
How long is my foot? We could measure it in
centimetres. How many centimetres long is my
foot? Take children’s suggestions and write
some on the board. Demonstrate measuring
the length of your foot to the nearest whole
centimetre using several paper decimetre
strips and cutting the last one to the exact
length.
Draw round your outstretched hand and show
children how to measure a hand span. Do you
think your hand span will be more or less than
20cm?
each one. Children take it in turns to be
the one lying on the floor. Each child
records her or his own height/length,
e.g. I am 12 rods long.
to talk of half a strip, if it is not
an exact number, e.g. it is four
and a half strips long.
 Thin card
 Scissors
 Template for
decimetre
strips (see
resources)
 Pens
Group of 6-8 children
Children work in pairs to drawn around
their hands, and use paper decimetre
strips to measure their hand span to
the nearest centimetre, recording this
on the drawing.
Work as a group to arrange their hand
spans in order of size.
Harder: Some children may be able to
measure to the nearest half
centimetre.
Give each child a sheet of A5
paper and ask them to work in
pairs to draw round their
partners’ foot and then to
measure the length of the foot
outline to the nearest centimetre
– using several decimetre strips
made of paper so they can cut the
last one to the right length. They
needn’t take off their socks! They
record the number of
centimetres long.
NB: Keep these sheets for
teaching sequence D1.
Harder: Some children may be
able to measure to the nearest
half centimetre.
 Decimetre
strips made of
paper (lots)
 Thin card
 Scissors
 A5 paper
 Pens
© Original teaching sequence copyright Hamilton Trust, who give permission for it to be adapted as wished by individual users.
Y2 Maths TS_M1 – Aut – 4days
Show the class a 30cm ruler. Point out and
demonstrate that this is the same length as
three decimetres – it is 30 centimetres long.
Show that this is true by laying three
decimetre rods or strips along the ruler!
Show children a metre stick. This is as long as
ten decimetre strips. Demonstrate that this is
true by laying ten strips along the metre. How
many centimetres long is the metre? Yes it is
one hundred centimetres long.
Now give each child a 30cm ruler. Where does
10cm come up to on this ruler? Can you see
anything in the classroom that might be less
than 10cm long? Draw the following table and
list their suggestions in the appropriate
column:
Less than
10cm
Between
10cm and
30cm
Between
30cm and
100cm
More than
100cm
Choose a few to check.
How long is your ruler? Can you see anything
than might be longer than 10cm, but shorter
than 30cm? Choose a few to measure. Can you
see anything that is longer than your ruler,
30cm, but shorter than a metre? Choose a few
to measure.
Can you see anything longer than 100cm?
Choose a few to compare against the stick.
Group of 4-5 children
Make a short ramp from a piece of card
on a large book. We’re going to roll cars
down this ramp, and measure how far
they travel along the ground at the
bottom of the ramp. Show this with one
car, and use the decimetres to measure
the distance rolled across the floor.
Count in tens to get the distance in
centimetres. Check if this is more than
one hundred centimetres. If so, point
out that we can use a metre stick.
Write the total distance in centimetres
on a Post-it™ and stick it to the car.
Take a different car. Do you think this
car will roll further or not? How far do
you think it might roll? Ask a child to
let it go at the top of the ramp, and
another pair to measure the distance it
rolls. Did this car roll further or not?
Write the distance rolled on a Post-it™
and stick it to the car.
Repeat with each car.
Ask children to arrange cars in order
according to the distances they rolled.
Easier: Make the ramp less steep so
that the cars roll a shorter distance.
The numbers of centimetres are likely
to be within the children’s range.
Harder: Children's estimations may be
more accurate.
Children choose six things on
their tables to measure using
cubes, e.g. rubbers, pencils,
books, pencil pots, ruler,
whiteboard, zip wallet etc. If
there are insufficient items to
measure, add some to each table.
Ensure that there are items less
than 10cm and things between
10cm and 30cm and some over
30cm.
Without measuring them, but
using estimating to help, they
work in pairs to sort them into
two groups as on the table (see
resources), and then use rulers or
cubes to measure the length of
each. They write the items and
their lengths in the correct
columns on the table.
Easier: Children sort items into
two groups, those which they
think might be shorter than 15cm
and those with they think might
be longer than 15cm (see
resources).
Harder: Some children may be
able to measure to the nearest
half centimetre.
© Original teaching sequence copyright Hamilton Trust, who give permission for it to be adapted as wished by individual users.
 Metre stick
 30cm rulers
 Piece of A4
card and book
 Selection of
different sized
cars
 Post-its™
 Objects less
than 50cm for
children to
measure
 Tables to
record
measurements
(see resources)
Y2 Maths TS_M1 – Aut – 4days