Transcript Numeracy Workshop 2

Multiplication & Division
St.Mary’s Catholic Primary School
Multiplication and Division
• As with addition and subtraction, there is a
structured path, building upon the children’s
knowledge of number and times table facts.
• In Years 1 and 2, children count in twos and
fives forwards and backwards, breaking off
‘sticks’ of cubes; how many twos make 20?
Multiplication
• They also begin to know doubles of small
numbers, and corresponding halves.
• Knowing that 10 + 10 + 10 = 30.
• Knowing that 10 x 3 = 30, and 30 divided by 3 =
10.
• Knowing that multiplication is repeated addition
is vital.
Multiplication and Division
• In Yrs 2, 3 and 4, the children will work with
larger numbers, for example;
• Double 17 is double 10 plus double 7, which is
20 + 14 = 34.
• The children will also develop their skills in
multiplying and dividing by 10, 100 and 1000.
Multiplication and Division
• Using knowledge of times tables may be done
as:
• 12 x 24 =
• 10 x 24 = 240
• 2 x 24 = 48
240 + 48 = 288
Multiplication
• In year 4, the children move on to non-standard
expanded written methods, for example, the grid
method.
• Again, the children are breaking down the
numbers into their place value.
• The children use prior knowledge to calculate,
30 x 70 as 30 x 7 = 210 and 210 x 10 = 2100.
Multiplication
• Breaking down the numbers into their factors.
• The children may explore the strategy of
partitioning.
Multiplication
• The children may then move onto long
multiplication strategies.
13
x 23
39
260
299
Division
• The children will meet division in KS1 as
sharing. They will carry out lots of ‘hands
on’ activities with different every day
objects.
Division
• Division is based on knowledge of the times
table facts and therefore, it is essential that
children know all their times table facts in Key
Stage 2.
• Division is closely related to multiplication, but is
essentially repeated subtraction.
• Possible strategies used may be:
• The children use their mental skills to calculate
that 47 ÷ 5 = 9 r2.
• Or 120 ÷ 10 = 120 put into groups of 10.
Division
• They may use prior knowledge of halving:
• 472 ÷ 4 as half 472 is 236, and half 236 is 118.
• The children will become accustomed to using a
multiples method for division, which in Year 5 we
fondly call the ‘bus shelter’ method.
Ways Ahead!
• Division is a tricky calculation and needs
lots of time to embed the steps. This has
been a whistle stop tour through the
stages.
• Therefore, please speak to your child’s
teacher if you would like further support.