Maths Evening Powerpoint

Maths is like true love, a simple idea

but can get complicated!

This evening I will…

• Inform you how and why we teach the four operations (addition, subtraction, multiplication and division) at the Preston Primary so that you can help your child in their maths activities.

Your child will learn…• How to add effectively.

Addition

Use of the hundred square

Use of place value cards

23 = 20 + 3

Use of place value cards for addition.

Rules for Expanded Column Addition

A few tips to help you out!

Expanded column addition

135

+ 42

7 (5 + 2)

70 ( 30 + 40)

100 ( 100 + 0)

177

Column addition using carrying

348 +

245

1

348 +

245

3

348 +

245

593

Your child will learn…• How to subtract.

Subtraction

Subtraction

• Children start by recording subtraction using calculations with pictures. This helps them to develop a mental picture of the number system in their head.

Use of the hundred squareFind ten more and ten less than a given number

SubtractionIn Key Stage 1 children then use number lines (counting on OR backwards) practically and written to solve calculations. Also known as finding the difference. Number lines are powerful images to help children develop mental methods for subtraction.

In Key Stage1…

• We teach the children to ‘count on’ on a number line when there is a small difference between numbers.

• For example: 82 - 78

78 80 82

+2 +2

In Key Stage 2 children:

•Again, use the number line to count up to the nearest 10 and count on.

45 – 16 =16 → 20 → 30 → 40 → 45 = 4 + 10 + 10 + 5 = 29

16 4520 30 40

4 10 10 5

Gradually you need less jumps.

Pencil and paper calculations

The numbers on the top row are partitioned (split up into tens and ones) to make the subtraction possible.

.

Subtraction – decomposition

Many parents learnt this method mechanically using words like ‘borrowing’

and ‘paying back’. We now know children need a solid foundation using

previous methods to understand this ‘code’.

5 3 3- 1 8 7

3 4 6

4 12 1

Can get ‘messy’ if performing

a calculation like 2004 – 997.

Mental methods are quicker!

Your child will learn…• How to multiply.

Multiplication

It’s all about Groups

Multiplication means

groups of e.g. 3 x 2 means 3 groups of 2

Learn all tables by end of Year 5!

Multiplying by 10

When you multiply by 10,

all the digits move 1

place to the left and a

0 is added. 2 3

20 30

200 300

2000 3000

X 10

X 10

Multiplying by partitioning

45 x 6

40 x 6 =240

5x 6=30

240+30=270

This moves on to the grid method.

23 x 5 = ?

Partition the number larger number to make it easier for us to work out the answer.

23 = 20 + 3

Now transfer all the information we have onto the grid.

x 5

20

3

Firstly, times the digit on the top row by one of the numbers at the side. Write the answer on the grid.

Repeat for the other number.

x 5

20

3

100

15

Finally, add these two new numbers together.

= 115

37 x 8630 7 x

80

6

560

180 42

2400

+2580 602

2580

602

31821

+

Your child will learn…

• How to divide.

Division

Early division begins with sharing in practical activities.

Linking Multiplication

and Division

4 x 3 = 12

12 ÷ 3 = 4

3 x 4 = 12

12 ÷ 4 = 3

20 ÷ 4 =

Children need to recognise that it can mean

20 shared by 4

How many lots of 4 in 20?

Link to multiplication facts

Using a empty number line to divide

56 ÷ 4 =

56 ÷ 4 = 14

Bus stop method

• Try to use the 4 operations effectively in a range of real life situations (problem solving). Make maths real and fun for your children. Enjoy!

Thank you for reading

• Recommended reading:

Maths for Mums and Dads

by Rob Eastaway and Mike Askew

• Should you have any questions or queries, please get in touch with Mrs Brown,

• Numeracy Co-ordinator.