Transcript WELCOME TO OUR MATHS EVENING!

WELCOME TO
WEST HOATHLY
CE PRIMARY
SCHOOL’S
MATHS
EVENING!
What can a numerate child do?
By the age of 11 they should :
• Have an understanding of place value
• Know number facts
• Use number facts in calculations
• Use mental and written methods
• Use a calculator
• Explain their methods and reasoning
• Answers to calculations are feasible
Our Aim
The aim is for children to do mathematics in
their heads, and if the numbers are too
large, to use pencil and paper to avoid
losing track.
To do this children need to
learn quick and efficient methods,
including appropriate written methods.
BEGINNER: Begin to relate subtraction to ‘taking
away’. In practical activities and discussion begin
to use the vocabulary involved in subtracting.
• Everyday activities are used in class to encourage the practical
use of subtraction and the appropriate language, such as
registration, snack time and giving out of resources. Children need
to work out how many extra they have and take them away.
• We use a lot of songs to introduce the language and concept of
‘taking away’, such as ‘5 Currant buns in a bakers shop’. A wide
range of play activities such as farm animals, cars, bricks, and
beads are used to support children in early subtraction skills.
• At home these experiences can be developed through practical
activities such as shopping, laying the table and cooking using the
language ‘too many’, ‘take away’, ‘subtract’ and ‘how many are
left’
TARGET 1: Using practical apparatus count how
many are left within 5
• We start by using our most practical
resource…….our fingers! (Five fingers take
away 1 finger = 4 fingers).
• This can be developed by using any objects that
the child is interested in such as cars, bricks and
beads etc.
• Unifix or Multilink cubes are a very helpful
resource as colours can be used to
demonstrate different amounts.
TARGET 2: To use number lines to solve and
record subtraction calculations.
• Use a number line to make ‘jumps’ back wards
to find the answer.
• 8-2 = 6.
• Check that the answer is always smaller than
the starting number. (This helps them jump the
right way on a number line and helps them
to learn to check their calculations early on)
TARGET 3:
UNDERSTANDING
SUBTRACTION AS
‘FINDING THE
DIFFERENCE’.
• How would you find the answer to
82 – 79?
YEAR 1: Find a small difference by
counting up.
For example: 4 – 2 =
You could hold the 2 in your head
and count on to the 4, thus finding
the difference.
YEAR 2: Recognise that
when finding the difference
between two numbers that
are close together, it is easier
to count up from the smaller
to the larger number, rather
than counting back.
TARGET 4: USING MARKED
NUMBER LINES TO
RECORD SUBTRACTION
CALCULATIONS BY
COUNTING ON:
USING A NUMBER LINE TO
DO THIS:
12 - 7
+ 3
7
+2
10
12
21 - 11
+ 9
11
+ 1
20
21
TARGET 5/6: USING AN
EMPTY NUMBER LINE TO
RECORD SUBTRACTION
OF LARGER NUMBERS BY
COUNTING ON FROM THE
SMALLER NUMBER TO THE
LARGER NUMBER
(COMPLIMENTARY
ADDITION).
USING AN EMPTY NUMBER
LINE TO DO THIS:
65 - 38
65 – 38 =
AND THIS…
242 - 165
242 – 165 =
Silent Subtraction Game!
Each person has one card with a
calculation on it. They have a short time
to work out their own calculation, then they
all have to stand in a line in the correct
order, highest answer to lowest
answer. So not only do they have to work
out their own answer, they have to work
out lots of others too!
Learning written methods is not
our ultimate aim.
Maths teaching today aims to develop
children’s mental strategies to support
written methods.
•Can I do this in my head?
•Can I do this in my head using
drawings or jottings?
•Do I need to use a written method?
•Do I need a calculator?
TARGET 7
Use refined methods of complimentary
addition to subtract whole numbers.
86 - 29
345 – 268
Have a go!
Target 8/9: Extend to decimals
75.6 – 28.2
92.46 – 58.7
Have a go!
Target 9/10: To use compact
method of decomposition to
subtract integers and decimals.
We do not teach children subtraction by
decomposition until they are very
confident using complimentary addition,
as many children make errors using
decomposition
Mistakes children make
4500
-3768
1200
4500
- 3768
1288
Can you see where the mistakes have
been made?
900000 3654
Some pupils will attempt subtraction
calculations using the formal written method,
failing to recognise that it would be more efficient
to calculate the answer mentally.
Partitioning leading to a compact
method
Have a go!
6500
- 1837
How can you help?
Talk about
how you
do maths
Give praise and
encouragement
Be positive
Ask your
child to
explain
Make sure maths is fun!