Transcript KS1 Addition - Houghton on the Hill C of E Primary School

plus
Before we can
start to teach
children how
to calculate
we teach
them about
the concept of
more and
less. As well
as have we
the same?
Addition
happens
when we gain
more.
The key factor to
finding an answer
is can your child
count reliably ?
We teach 1:1
correspondence
and a concrete
understanding of
number before we
start addition.
So once children
understand that 5
means 5 things and
they count reliably
saying the numbers
in order they start to
understand the
number line.
As we go up we get
more! So we teach 1
more then 2 more
so they understand
the answer is a
larger number.

When children have the basic mental
understanding of number and
remember the number line they are
ready to add.

We teach lots
of vocabulary
they need to
know .
We start practically to
check children
understand the
vocabulary, use it
correctly and most
importantly remember
the key factor of
counting reliably!!
But children quickly start to see
that we make numbers up by
combining other numbers if we
use other manipulatives such as
numicon. These are number
bonds.
Recording in number sentences brings
new vocabulary again.
Plus +
Equals =
Let’s not forget the
power of our fingers.
-> Show me 6!
As we move onto the
recording of sums we
let children show us
with pictures first.
Jottings become so
important as they
move through school.
The children do not
need to learn a
formal method yet.
As children understand they combine 2 sets to
add they also need to understand they count on
to add. This can then extend them to higher
numbers.
If we recall bonds of numbers we can then recall
pairs of numbers as we add to make it simpler.
7 + 5 =
 5+2
+5 =
5 + 5 + 2 =
 10 + 2 = 12
This splitting numbers is called
PARTITIONING.
The key bonds to start learning are
doubles and the number bonds to 10.
Using known facts and place
value to calculate addition.
We try to simplify calculations we do
mentally so…
14 + 4=
Take off the 10 first and calculate
4+4=8
Then add in the 10
so 8 + 10= 18
What do we mean by
place value?
Tens and Ones
The digit 5 occurs in each of these numbers:
15
56
75
It has a a different value in each case because of its position.
In 15 the 5 stands for 5 ones.
In 56 the 5 stands for 5 tens.
In 75 the 5 stands for 5 ones.
Partitioning using place value into
tens and ones.
47 + 25 = ?
It does help to see it visually so children still work
practically but also need to remember to make jottings
even with larger 2 digit additions.
So we continue to use number lines to
develop their understanding.
How to count on in tens and ones
+10
23 + 12 = 23 + 10 + 2
= 33 + 2
= 35
23
+2
33
35
Partitioning and bridging through 10
The steps in addition often bridge through a
multiple of 10
e.g. Children should be able to partition the
7 to relate adding the 2 and then the 5.
8 + 7 = 15
Adding 9 or 11 by adding 10 and
adjusting by 1
e.g. Add 9 by adding 10 and adjusting by
1
 35 + 9 = 44

Using the inverse relationship

If you draw a long rectangular box and then label it with
the total number.
15

Underneath it you can then have another box with the
number bonds to make that number.
15
12


3
This is called the Singapore bar method because children in
Singapore are taught from a very early age to solve
problems using the bars.
To find out more go to www.mathsnoproblem.co.uk
HELPING
AT
HOME
Please don’t show you are scared of maths!
 Make a simple peg abacus to hang up.
 Play more board games eg. monopoly.
 Use 2 dice in every game.
 Play number pairs- who can be closest to
10, 20, 100 depending on ability.
Add in strategy by playing games rather
than straight recall or rote learning.
-> We need mathematical thinkers !!!

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