Transcript How is multiplication taught at Barnsbury?

Barnsbury Primary School
Understanding and Applying
Mathematical Calculations
Today’s Objectives

To understand key mathematical
calculations and methods

To understand how problem solving is
taught

To model and explore mathematical
calculations
Why is maths important?
“ A person's success in life depends on
how well she/he can solve problems.”
“Doing a maths problem helps practice
the problem-solving steps that apply
to everyday situations: define the
problem, think of ways to solve it,
implement a solution, and evaluate
the results.”
How do children learn about
numbers?

Nursery rhymes

Counting objects into the toy box when
tidying up

Ordering numbered objects

Comparing who has more fish fingers on
their plate
How is addition taught at
Barnsbury?
What different words can you
think of for addition?
How is addition taught at
Barnsbury?
How is addition taught at
Barnsbury?

Combining two groups of objects

Use correct mathematical notation +

Count on in ones along a number line

Understand addition can be completed in any
order so putting the biggest number first

Understand partitioning in order to use this skill
to add
=
How do we partition at
Barnsbury?
TU
46
40
6
TU
82
80
2
Can you partition 37?
How is addition taught at
Barnsbury?


Adding a one and two digit number using a
number line
E.g.
13+6= 19
+1
13
+1
14
+1
15
+1
16
+1
17
+1
18
19
How is addition taught at
Barnsbury?


Adding 2 two digit numbers using a number line
using partitioning skills
E.g.
18+25= 43
+10
25

+1
35
+1
36
+1
37
Can you solve 14+27=?
+1
38
+1
39
+1
40
+1
41
+1
42
43
How is addition taught at
Barnsbury?

Adding 2 two digit numbers by partitioning,
adding and recombining

E.g.
32+15=
30
30+10=40
2+5=7
40+7=47
2
10
5
How is addition taught at
Barnsbury?

Adding 2 two digit numbers using partitioning
knowledge and the expansion method.
48 + 36=
40 + 8
30 + 6
80 + 4
10
How is addition taught at
Barnsbury?

Adding 2 two digit numbers using standard
written method (column method).
33 + 58=
T
5
+3
9
1

U
8
3
1
Can you solve 49+26=?
How is subtraction taught at
Barnsbury?
Can you think of different
mathematical vocabulary for
subtraction?
How is subtraction taught at
Barnsbury?
How is subtraction taught at
Barnsbury?

Counting backwards in one’s

Having a given number of objects and taking
some away and counting the number left at the
end

Using the correct mathematical notation -

Subtracting single digit numbers using a number
line

Subtracting 10 from any given number mentally
=
How is subtraction taught at
Barnsbury?

Subtracting a two digit number from a two digit
number using partitioning skills along a number
line
Using your new knowledge of adding using
partitioning and a number line could you have a go
at subtracting using similar skills?
49-26=
How is subtraction taught at
Barnsbury?

Partitioning the number that needs to be
subtracted (always the smaller number)
38-15=
10
5
38-10=28
28-5=23
How is subtraction taught at
Barnsbury?


Partitioning the number that needs to be
subtracted crossing the tens border
32-15=
10
5
32-10=22
22-5=17

Can you solve 73-27=?
What method do you now
know that could help you
complete this step?
How is subtraction taught at
Barnsbury?

Subtracting 2 two digit numbers using partitioning
knowledge and the expansion method.
52 - 36=
40
+10
50 +
- 30 +
10 +
2
6
6 = 16
How is subtraction taught at
Barnsbury?

Subtracting 2 two digit numbers using standard written
method
74 - 47=

TU
6
1
74
-47
27
Can you solve 82-38=?
How is multiplication taught at
Barnsbury?
What mathematical vocabulary can
you think if that also means
multiply?
How is multiplication taught at
Barnsbury?
How is multiplication taught at
Barnsbury?

Counting up in 2’s

Counting up in 5’s

Knowing doubles of numbers

Learning multiplication facts
How is multiplication taught at
Barnsbury?

Understand multiplication as repeated
addition
3 + 3 + 3 + 3 = 12
4x3
3 multiplied by 4
4 lots of 3
How is multiplication taught at
Barnsbury?

Understand multiplication as an array
Understand multiplication can be
completed in any order
2x4
4x2

How is multiplication taught at
Barnsbury?

Understand how to represent an array and
therefore successfully multiply using a
number line.
4x2 or 2x4
How is multiplication taught at
Barnsbury?

Use knowledge of factors to multiply
Understand that
24 x 20 = 24 x 2 x 10
How is multiplication taught at
Barnsbury?

Use partitioning knowledge to complete
grid method for multiplying numbers with
two digits
10
13x4=
3
10 3
X
4
40
12
40+12=52
4
40
12
How is multiplication taught at
Barnsbury?

Use partitioning knowledge and multiplication factor
knowledge to complete grid method for multiplying two
digit numbers over 10
10
4x23
10
3
4
Or
10 10 3
X
40
4
40
40+40+12=92
12
Or
X
4
20
3
80+12=92
80
12
How is multiplication taught at
Barnsbury?

Use grid method to multiply 2 two digit numbers
14 x 26 = 364
X
20
6

10 4
200
80
60
24
200+80+60+24=364
Can you use grid method to solve 25x19=?
How is multiplication taught at
Barnsbury?

Use lattice/glacier method to multiply 2 two digit numbers
32 x 16=
3
0
0
2
0
+1
3
1
5
1
2
1
2
6
1
8
2
How is multiplication taught at
Barnsbury?

Use the standard written method
56
x 27
392
1120
1512
(56x7) Bottom line when using grid method
(56x20) Top line when using grid method
1

Can you use this method to solve 42x26=?
How is division taught at
Barnsbury?
What mathematical vocabulary
can you think if that also means
divide?
How is division taught at
Barnsbury?
How is division taught at
Barnsbury?

Counting back in 10’s

Counting up in 5’s and 2’s

Knowing halves of numbers
Using known multiplication facts to
identify corresponding division facts
e.g. 2x10=20
20÷10=2 or 20÷2=10

How is division taught at
Barnsbury?

Understand division as sharing
How is division taught at
Barnsbury?

Understand division as grouping through
use of arrays (as used in multiplication)
12 divided into
groups of 3 gives
4 groups
12  3 = 4
12 divided into
groups of 4
gives 3 groups
12  4 = 3
How is division taught at
Barnsbury?
Understand division as grouping
 Link the idea of grouping as repeated
subtraction

15÷3=5
0
3
6
9
12
15
How is division taught at
Barnsbury?

Represent division using multiplication
facts along a number line
100÷7=
10x7
0
14 r 2
1x7
1x7
1x7
1x7
2 left
70
77
84
91
98
100
How is division taught at
Barnsbury?

Use chunking of multiplication facts
518 ÷ 7 = 74
518
What facts do we
know about the 7
times-table?
- 350 ( 50 x 7 )
168
- 140
Fact Box
( 20 x 7 )
28
- 28
2 x 7 = 14
5 x 7 = 35
(4x7)
0

1x7=7
Can you solve 335÷5=?
10 x 7 = 70
20 x 7 = 140
50 x 7 = 350
100 x 7 = 700
How is division taught at
Barnsbury?

Use the standard written method for long
division
518 ÷ 7 = 74
7
518
- 350
Direct link to
chunking
168
- 140
28
-
28
0
How do we solve mathematical
problems at Barnsbury?
It's really simple, just RUCSAC:
Read (the question
carefully)
Understand (what the problem is)
Choose (important numbers and operation
needed)
Solve (use number skills to solve
calculation, showing working out)
Answer (write down the answer)
Check (your answer makes sense)
RUCSAC
Jack has 7 bags of apples. In each bag
there are 8 apples. If he shares them
equally amongst his 4 friends how many
apples do they each have?
Today’s Objectives

To understand key mathematical
calculations and methods

To understand how problem solving is
taught

To model and explore mathematical
calculations
On reflection…
 With
a partner
what two things
do you feel more
confident about?
 Will you be
happier to help
your child?