Transcript FSworkshop - Giffards Primary School

Welcome to the Year 6
Numeracy Workshop
th
18
Friday
February
1
Aims for today.
To show you what is expected of children
in numeracy in Year 6
To show you how we teach your children a
variety of strategies to solve mathematical
problems.
To provide you with the chance to ask
questions and chat with other parents and
the teachers.
To give you ideas and ways to help your
children at home.
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Multiplication and division
• use mental calculation strategies for multiplication and
division.
• use mental methods for calculations including decimals.
• Know when to use mental methods, when to use a
written method
• Use an efficient written method for multiplication and
division
• TU x U TU x TU TU ÷ U TU ÷ TU
• Solve real life problems
3
Mental test questions
5 seconds
Multiply 60 by 10
10 seconds
Divide 350 by 100
How would you work these out?
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How would calculate these
mentally?
12 x 10
12 ÷ 10
12 x100
12 ÷100
12 x 1000
12 ÷1000
Must understand place value and the value
of each digit in a number and a decimal
5
Th
H
1
T
U
.
1/10
1
2
.
0
2
0
.
0
1
2
.
0
1
.
2
1/100
1/1000
1.2 divided by 10?
1.2 divided by 100?
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Children manipulate numbers
• Multiply move digits to the left
• Divide move digits to the right
• Decimal point stays constant
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14 x 10
14 ÷by 10
14 x 100
14 ÷ by 100
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Calculate 17 × 5 × 4
1 mark
How would you work this out in 3 – 5 minutes?
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Children must know the value of each digit.
Partitioning helps them to learn the value of the digits.
.
Will lead to methods of long multiplication.
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Higher order mathematicians
17 x (4x 5) =
17 x 20 =
11
To calculate this children must know their tables
Must have an efficient method
Must be able to check their answers
Use partitioning to gain understanding of values
17 x 5
10 x 5 = 50
7 x 5 = 35
50 + 35 = 85 must also be able to add
12
85 x 4
80 x 4 = 320
5 x 4 = 20
(8 x 4 x 10 )
320 + 20 = 340
17 x 5 x 4 = 340
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The Grid Method
x
10
7
5
14
The Grid Method
x
10
7
5
50
35
50 + 35 = 85
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The Grid Method
x
80
5
4
320
20
320 + 20 = 340
16
23 x 16
17
The Grid Method
x
20
3
10
200
30
6
120
18
320
48
18
320 + 48 = 368
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• Use the grid method to calculate
• 18 x 6
• 18 x 16
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Plastic cups are sold in packs of 8
Amir needs 27 cups.
How many packs must he buy?
_____________ packs
How would you work this out in 5 minutes without
a calculator?
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48 ÷ 3 =
How many 3s in 48
Share 48 by three
Three times table
48 is made from an amount of 3s
3 x _ = 48
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Using a number line to learn that 48 is made
from an amount of 3’s
Chunking in multiples along the number line
to make this more efficient and quicker to
calculate
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Chunking
moving to a formal written method
(Subtracting multiples of 3 )
48 ÷ 3 = 16
48
30 10 x 3
18
18 6 x 3
0
1x3
2x3
5x3
10 x 3
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Multiplication the inverse of division
The Grid Method to check division
x
10
6
3
30
18
30 + 18 = 48
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90 ÷ 6 =
1x6
2x6
5x6
10 x 6
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27 ÷ 8 =
1x8
2x8
What do we get with this problem?
How is that dealt with?
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Subtraction and addition
• Develop and refine written methods for addition
and subtraction building on mental methods
• Add by partitioning
• Add using the column method
• Find the difference by counting on on a number
line
• Subtract using exchanging and decomposition
(column method)
• Solve real life problems
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How would I work
this out?
What do the words
mean?
What maths is
required?
What calculations
need to be used?
A shop sells three types of
sunglasses.
What is the difference in price
between
the most expensive and least
expensive
sunglasses?
£
1 mark
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Column Subtraction
£5.85 - £2.99
£5. 85
£2. 99
Children need to understand place value
and exchanging.
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Use of a number line to find the
difference
• Giving change in the shop
• Count on in amounts
£2.99 on £0.01 to £3.00
£3.00 on £2.00 to £5.00
£5.00 on £0.85 to £5.85
£0.01 + £2.00 + £0.85 = £2.86
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High order mathematicians would
use their mental skills
• Round £2.99 to £3.00
• Subtract £3.00 from £5.85
• Add back a penny
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I spend £4.32 on food and £3.62 on drinks
How much change to I get from £20.00?
Pineapples £1.40 each
Grapes are £2.25 for 1KG
I buy one pineapple and half a kilogram of grapes.
How much change will I get from £5.
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Add money amounts
Subtract answer from £10
Ryan buys the £4.69 sunglasses and a sun
hat.
How much change does he get from £10?
Show
your working.
You may get
a mark.
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Fractions, Percentages, Decimals
Doubling and Halving
• ¼ of 600? ¼ of 800
Half and half again
Divide by 4
Half of 27? Half of any odd number?
Dealing with an odd number and a decimal
27 = 20 and 7 10 + 3.5 = 13.5
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Applying multiplication and division knowledge and skills
- Fractions of quantities
• 1/4 of 24
Divide by 4
1/8 of 24
Divide by 8
• 1/6 of 18
• Divide by 6
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Applying multiplication and division knowledge and skills
- Fractions of quantities
2/4 of 24 =12
divide by denominator 4
24÷4 = 6
and multiply by numerator 2
6x2 = 12
3/8 of 24 = 9
24÷8 = 3
3x3=9
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Percentages
•
•
•
•
1 % divide by 100
10% divide by 10
5 % find 10% and half (divide by 2)
20% find 10% and double (multiply by 2)
• 61% find 1% (divide by 100) and multiply
by 61
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• Reduce the price of these trainers by 15%
• What is the new price?
• Trainers cost £26.00
£2.60 + £1.30 = £3.90
£26.00 - £3.90 =
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• 60 x 10 =
• 60 divided by 100 =
• 17 x 5 x4 =
• 48 ÷ 3 =
• You buy two items for £1.75 and £3.62 –
What change would you get from £10 ?
• What is half of 49?
• Find 15% of 400
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Ways to help
• Ensure your child knows their times tables and division
facts; then extend this
e.g. 30 x 6
420 divided by 7
• Improve their mental addition or subtraction skills by
asking them questions on the way to school e.g. 67+43.
You can make this fun!
• Ensure they do their homework ( remember this will only
get more frequent in year 7!)
• Encourage them to do their best!
• Practising halving and doubling numbers
• Talking about real life maths situations – adding and
finding the change
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