Transcript maths workshop - four operations

Maths is like…..
• Train-spotting…..you jot down a
whole load of numbers for no
apparent reason
• Cabbage…..you either love it or
hate it depending on how it was
served up to you as a child
Aims of session
•
To work through each of the methods we
teach at Rushen Primary for addition,
subtraction, multiplication and division.
WHY?
•We want children to develop efficient methods of calculations
with addition, subtraction, multiplication and division.
•We want children to be able to choose an appropriate method
for their calculations.
•We want children to develop a mathematical understanding,
a feel for number not just a mechanical method that is prone to
error.
•We want to develop “learners for life”.
Language of addition.
Addition
Sum
Make
altogether
Plus
More
Add
Total
•
Methods of addition.
Starting with knowing number bonds, use of
apparatus, adding groups of apparatus
together.
•
4
+
+
2 = 6
1+1+1
+
+
• Working across the
line adding significant
digits first ie in 14 +
15, add the tens first
and then the units.
Need to have sound
place value
understanding before
doing sums like 16 +
18 where digits cross
the tens boundary.
Methods of addition.
• Column addition.
Digits with the same
value must be lined up underneath
each other. Once concept of adding
units first then tens is understood then
can work on where to put digits when
values break the tens boundary.
Language of subtraction.
Take away
Subtract
Less
Difference
Leave
Minus
Methods of subtraction.
•
Starting with knowing number bonds,
use of apparatus, taking groups of
apparatus away from a total - how many
are left.
•
4-2=2
Methods of subtraction.
• Working across the line
subtracting significant
digits first ie in 39 - 15,
subtract the tens first and
then the units. Need to
have sound place value
understanding before
doing sums like 34 - 18
where digits cross the
tens boundary. Use of
number lines to show
jumping or counting on
in stages.
Methods of subtraction.
• Column subtraction.
Digits
with the same value must
be lined up underneath
each other. Once concept
of adding units first then
tens is understood then
can work on what to do to
when a subtraction can’t be
done - borrowing from the
next column.
Language of Multiplication.
Multiplication
Array
lots of
Groups of
Times
Repeated addition
Multiply
Multiplied by
Multiple of
Multiplication facts - what are they?
•
•
•
Yr 4 - Know all multiplication facts to 10 x 10 and
division facts.
Multiplication facts are the times tables where two
numbers are multiplied. Children are expected to
be able to recall and make use of multiplication
facts up to 10 x 10 by end of Yr5. They are key to
many areas of maths not just multiplication and
division.
Yr 5&6 Using multiplication and division facts.
Ideas for revising and applying
multiplication facts.
• Reciting times table facts ie 1x4 is 4, 2x
4 is 8 etc.
• Round the clock
• Shopping
• Using playing cards
• Board games
Methods of multiplication HTU by U
Important
•Multiplying, product, units, tens, hundreds, multiple,
array, lots of, times, multiply, double.
•Refer to each number by its correct value - ie 5 or
40 or 300.
Grid Method
Formal Method
126 x 3
126 x 3
Methods of multiplication
HTU by TU
Grid Method
Formal Method
24 x 16
24 x 16
Language of Division.
Share
Equal groups of
Divided by
Share equally
Divide
Divided into
Methods of Division HTU by U
•
•
Words linked to division - group, divide,
division, divided by, divisible, factor,
share, half, remainder.
Need to know division facts - related to
times tables knowledge.
Formal method
196 ÷ 6
Methods of dividing
HTU by TU
Repeated subtraction
972 ÷ 36
Formal method
972 ÷ 36