Year 3 Teaching Sequence Summer 4 – Doubles, near doubles and halves (two days)
Prerequisites:
 Double two-digit numbers (totals more than 100) (see spring teaching sequence 4)
 Know double 1-20 by heart, and related halves (see spring teaching sequence 4 and summer oral and mental starter
bank 4)
Overview of progression:
Children use partitioning and recombining (Splits) to double multiples of 5 up to 100, and record the corresponding halves.
Through practice they begin to know these by heart or derive them very quickly. The same strategy is used to double
multiples of 50 from 50 to 500. Children use their doubles to find near doubles e.g. 80 + 81, 35 + 36.
Note that the concept of partitioning, doubling each part and recombining is an important one which can help with later
work in Year 4 on multiplying two-digit numbers by single-digit numbers, as well as adding pairs of two-digit numbers.
Watch out for children who double 45 and get 85, forgetting to double the 5, or who write 810 not thinking about what the
whole number means after doubling each part.
© Original teaching sequence copyright Hamilton Trust, who give permission for it to be adapted as wished by individual users.
Y3 Maths TS4 – Sum – 2days
Objectives:
 Know doubles of multiples of 5 to 100 (e.g. double 35) and corresponding halves, use near doubles e.g. 80 + 81
 Quickly derive doubles of multiples of 50 to 500 e.g. double 250.
Whole class
Group activities
Paired/indiv practice
Resources
What is double 50? Talk to your partner about
how you might work out double 55. Take
feedback drawing out double 50 to make 100,
doubling 5 to make 10 and adding 100 and 10 to
make 110. What strategy are we using? (Splits)
So what is half of 110? If we didn't know, we
could halve 100, and then halve 10 to find out.
Record:
Double 50 is 100, half of 100 is 50
Double 55 is 110, half of 110 is 55.
What is double 60? What double fact can we
use to help us?
If we know double 60, what do you think
double 65 is? How do you know? Record some
jottings on your whiteboards if it helps, e.g.
Double 65
Group of 4-5 children
Ask chn to write six multiples of 100 on
their whiteboards. Ask doubles
questions about multiples of 50 up to
double 500, such as: What is double
300? Double 450? Chn ring the answer
to their whiteboards if they have it,
the first child to ring all six numbers
wins. Repeat, building up speed as chn
become familiar with working them out.
Harder: After the first time of playing,
ask chn to choose six multiples of 100
to halve and to write these halves on
their whiteboards. Ask halving
questions such as: What is half of 300?
Chn take it in turns to choose a
number from a grid of multiples
of 5 (see resources). They double
it, their partner checks, and if
the answer is correct they ring
the number in their chosen colour.
They also record the double
ready for the next session. The
first child to ring four numbers in
a line (horizontally, diagonally or
vertically) wins. Afterwards they
work out any other doubles not
already calculated.
Easier: Chn work in pairs to
calculate double 5, double 10,
double 15… double 50 in order,
using jottings to help.
Harder: Chn take in turns to
choose a number from a grid and
halve it (see resources).
 Three-digit
place value
cards
 Activity sheets
of multiples
(see resources)
 Coloured
pencils
120
10
130
If double 65 is 130, what is half of 130?
Record: double 65 is 130, so half of 130 is 65.
© Original teaching sequence copyright Hamilton Trust, who give permission for it to be adapted as wished by individual users.
Y3 Maths TS4 – Sum – 2days
Repeat for double 70, 75, 80, 85, 90, 95 and
100, building up a table.
Give each pairs three-digit place value cards.
Cover up the table with a sheet of large paper.
What is double 65? Talk to your partner, and
then show me the answer using the place value
cards. Reveal the table so that they can check.
Repeat asking doubles, and then halves
questions asking chn to agree the answer with
a maths partner before showing the answer
using place value cards. Use the table to check
each time.
Talk to your partner about how we might work
out double 250. Take feedback, drawing out
doubling 200 and doubling 50, and then adding
400 and 100 together to make 500. Ask chn to
work in pairs to work out double 150, 350 and
450. Take feedback.
Display the table of double facts from the
previous session. What double could we use to
work out 45 add 46? Will the answer be more
or less than double 45? How much more?
Write 45 + 46 = 91 at the side. We could use
double 45 to help us find the answer to other
near doubles. What might they be? Take
feedback, and write near doubles such as 45 +
44, 45 + 47 by the side.
Repeat with 80 + 81, 65 + 64 and 40 + 39.
Group of 4-5 children
Write double 35 is 70 in the middle of
the flipchart. If we know this fact what
other facts could we work out? Build up
a fact web to include facts such as half
of 70 is 35, 35 + 34, 35 + 36, 350 +
350, half of 700 is 350, 350 + 351, 350
+ 349, and 350 + 360.
Easier: Begin with double 40.
Harder: Begin with double 75.
Chn are given a list of near
doubles to calculate (see
resources). They work in pairs to
look at their doubles from the
previous session and discuss which
will help. They record the doubles
alongside the answers, e.g. 80 + 81
= 161.
Easier: Chn only use doubles up to
double 50 (see resources).
© Original teaching sequence copyright Hamilton Trust, who give permission for it to be adapted as wished by individual users.
 Table of
doubles facts
from previous
session
 Activity sheets
of near doubles
(see resources)
Y3 Maths TS4 – Sum – 2days