Transcript Multiplication

What do we teach in KS1 Maths?
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Number bonds from 10 and 20 ( ie 7+3=10, 18+2= 20)
Basic multiplication ( 2,5,10)
Basic division ( 2)
Fractions ( ½ , ¼, 1/3 )
Addition and subtraction to 100
Place value ( units, tens and hundreds)
Time ( o’clock, half past, quarter to, quarter past)
Measurement ( weight, length, capacity)
Money ( everyday money- calculating change)
Problem solving
Handling data ( graphs, tables, sorting data)
Shape and space
Today we will focus on multiplication and division
Maths – when do we use it?
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Division
Division vocabulary
share
o share equally
o divide
o divided by
o groups
o halve
o half
o
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Sharing objects
Share these six biscuits between three teddies.
How many biscuits does each teddy get?
Linking with halving and quartering shapes
Splitting into equal groups/parts
½
¼
¼
¼
¼
½
Using tens and units to solve division problems
48
12 ÷ 4 = 3
48 ÷ 2 = 24
15 ÷ 3 = 5
Division as grouping
Can you group these cookies into groups of 3?
How much does each teddy get?
Division as grouping – Repeated Addition
+3
0
+3
3
15 ÷ 3 = 5
+3
6
+3
9
+3
12
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Arrays as a tool for solving answers
18 ÷ 6 = 3
18 ÷ 3 = 6
Link with multiplication
Remainders
13 ÷ 4 = 3r1
+4
0
+4
4
13 ÷ 4 = 3r1
+4
8
+1
12
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So how can you work out a division
calculation using times tables?
Count in 2s until you get to 16.
2 4 6 8 10 12 14
16
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Division using an empty number line
How many groups of 5 are there in 25?
25 ÷ 5 = 5
5
0
5
5
5
10
5
15
5
20
25
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Resources to help children with division
½
½
Your turn!
There are 30 children in the class. They need to be
in teams of 5. How many teams will there be? Use
an empty number line to work it out.
5
0
5
5
5
10
5
15
6 groups of 5 make 30.
5
20
5
25
30
So 6 teams.
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Multiplication
Multiplication
Counting in 10s
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Multiplication
Counting in 2s
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Multiplication
Counting in 5s
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Multiplication
• Children
need to learn multiplication tables and multiplication
facts.
• Yes – learn to recite tables but also need to know table facts at
random.
• e.g. 8 lots of ten are?
• And answer questions like “ How many tens in 80?”
• Not secure in times tables until able to do this quickly.
Should be working on 10x, 2x and 5x tables in Year 1, continue and
work on 3x and 4x in Year 2. Secure in Year 3.
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Multiplication
Problem solving
There are 10 pencils in a pack.
How many pencils are there in 4 packs?
Repeated addition
10 + 10 + 10 + 10 = 40
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Multiplication
3 times 5 is the same as 5 + 5 + 5 = 15 or 3 lots of 5 or 3 x 5
On a number line
5
5
0
5
5
10
15
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Multiplication
Across the
corridor and
down the
stairs!
As an array
3 x 5 = 15
5 x 3 = 15
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Problem solving
Ella’s dad washes some cars. He
uses 12 buckets of water. Each
bucket has 5 litres of water. How
many litres of water does he use
altogether?
There are 15 apples in a tray. Ling
has 4 trays of apples.
How many apples does Ling have
altogether? Show how you work
it out.
Your turn! Can you draw pictures or make jottings to show how you could
work one or both of these out?
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Resources to help children with multiplication
Practical maths
Making maths practical by using real materials. Try
some of these at home with your child.
 Using coins
using food
 Using measuring cups
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cooking
Useful websites
http://www.familylearning.org.uk/multiplication_games.html
http://www.ictgames.com/resources.html
http://www.bbc.co.uk/bitesize/ks1/maths/
http://www.comberps.newtownards.ni.sch.uk/maths_games_for_ks1.htm
http://www.maths-games.org/time-games.html
http://www.bbc.co.uk/schools/websites/4_11/site/numeracy.shtml
http://www.woodlands-junior.kent.sch.uk/maths/index.html
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