sijs division policy - st ives junior school...counting up and down in 10s using place value chart...
TRANSCRIPT
1
Objective and
Strategies
Concrete Pictorial Abstract
Halving in
practical
contents linked
to simple
problem solving
Start with links to real
life events. Cut a cake in
half, both halves being
exactly the same size.
Encourage children to use mark-making to support their
thinking about numbers and simple problems.
Sharing into two
groups linked to
simple problem
solving??
Share four cars between
two friends.
Counting beads, using
both hands to share the
beads in middle into two
ends.
How many different ways can you show half on the ten frame/bar/
grid/counting stick?
Part/part whole
Encourage children to use mark-making to support their
thinking about numbers and simple problems.
Halving by partitioning??
With decimals??
SIJS Division Policy
2
Objective and
Strategies
Concrete Pictorial Abstract
Sharing into
groups
I have ten cubes. Can
you share them equally
in 2 groups?
Share 9 buns between 3 people.
9÷3=3
9÷__=3
Recall division facts related to times tables.
3
Objective and
Strategies
Concrete Pictorial Abstract
Division as
grouping
Divide quantities into
equal groups. Use cubes,
counters, beads and
objects to aid
understanding.
Use a number line to show jumps in groups. The number of jumps
equals the number of groups.
Think of the bar as a whole. Split it into the number of groups you
are dividing by and work out how many would be within each group.
Use sections on a counting stick.
28÷7=4
Divide 28 into 7 groups. How many are in each group?
How many groups of 3 in 12?
How many jumps to get to 12?
Use x table grid
4
Objective and
Strategies
Concrete Pictorial Abstract
Dividing multi-
ples of 10, 100
and 1000 by 10,
100 and 1000
Pupils use the
strategy of shar-
ing into equal
groups of tens,
hundreds or
thousands to
reinforce their
understanding of
place value
Using beadstring
30÷10=3
Back of 100 square and Juli’s pictorial grid to show 1/10 and 1/100
6000÷200=30
I know there are five groups of 200 in 1000 and I have six
1000s and 5x6=30.
Place value chart
÷10 to the right one jump
÷100 to the right two jumps
Then zero the hero flies off
10x__ = 100x24
Odd ones out
0.7x100, 7x10, 0.07x1000
Division within
arrays
Link division to multipli-
cation by creating an
array and thinking about
the number sentences
that can be created.
E.g.
15÷3=5 5x3=15
15÷5=3 3x5=15
Draw an array and use lines to split the array into groups to make
multiplication and division sentences.
Find the inverse of multiplication and division sentences by
creating four linking number sentences.
7x4=28
4x7=28
28÷7=4
28÷4=7
5
Objective and
Strategies
Concrete Pictorial Abstract
Division with a
remainder
14÷3=
Divide objects between
groups and see how
much is left over.
Jump forward or back in equal jumps on a number line then see how
many more you need to jump to find a remainder.
Draw dots and group them to divide an amount and clearly show a
remainder.
14÷3=4r2
Complete written divisions and show the remainder using
r.
72 children are going on a trip with 4 teachers. A bus has
20 seats. How many buses should they book?
A 1m piece of ribbon is cut into equal pieces and a piece
measuring 4cm remains. What length could the equal piec-
es be? How many ways could the ribbon have been cut
into equal lengths?
6
Objective and
Strategies
Concrete Pictorial Abstract
Short division Use place value /
partitioning with Dienes.
448÷4=112
852÷4=213
8 hundreds shared into 4
equal groups
5 tens shared into 4
equal groups
(Regroup 1 ten for 10
ones)
12 ones shared into 4
equal groups
Students can continue to use drawn diagrams with dots or circles to
help them divide numbers into equal groups.
Encourage them to move towards counting in multiples to divide
more efficiently.
Begin with divisions that divide equally.
Move onto divisions with a remainder.
7
Objective and
Strategies
Concrete Pictorial Abstract
Long division The short division
method can be applied
for 11 and 12 using
times table knowledge.
Factors should be used
to break down the
calculation and apply
the short division
method.
1
Objective and
Strategies
Concrete Pictorial Abstract
Doubling Use practical activities to
show how to double a
number.
Double 3 is 6
Draw pictures to show how to double a number.
Double 3 is 6.
Multiply by 4 by doubling twice.
Multiply by 8 by doubling three times.
Partition a number and then double each part before re-
combining it back together.
What is the relationship between 3x2, 3x4 and 3x8?
I double a number and my answer is 64. What is the num-
ber?
SIJS Multiplication Policy
2
Objective and
Strategies
Concrete Pictorial Abstract
Repeated
addition
Use different objects to
add equal groups.
3+3+3
0.2 + 0.2 + 0.2 = 0.6
Write addition sentences to describe objects and pictures.
Write a story for … Include jottings.
Write addition statements as multiplication statements.
True or false? 7+7+7 is the same as 7x4?
3
Objective and
Strategies
Concrete Pictorial Abstract
Counting in
multiples
Count in multiples
supported by concrete
objects in equal groups.
X table grid
Use a number line with kangaroo character or pictures to continue
support in counting in multiples.
Use counting stick.
Count in multiples of a number aloud.
Write sequences with multiples of numbers.
2, 4, 6, 8, 10
5, 10, 15, 20, 25, 30
If I know 7x5, how does this help me with 8x5?
Missing number sequences including negative numbers
and decimals.
Count in multiples of 5 starting on a non-multiple of 5,
e.g. 3
4
Objective and
Strategies
Concrete Pictorial Abstract
Arrays - showing
commutative
multiplication
Create arrays using
counters/cubes to show
multiplication sentences.
Draw arrays in different rotations to find commutative multiplication
sentences.
Link arrays to area of rectangles.
Use an array to write multiplication sentences and
reinforce repeated addition.
5+5+5=15
3+3+3+3+3=15
5x3=15
How many different ways can you make 16 using
multiplication?
Sam is planting 12 onions. He wants them to be in equal
rows. How many different ways could he arrange them?
5
Objective and
Strategies
Concrete Pictorial Abstract
Times tables
using known
facts
E.g. double x2
table to find x4
table facts or
double 6x5 to
find 12x5
Use counters, beads and
cubes.
Multiplication grid
Using jottings, explain the relationship between 3x4 and
4x3.
If you know 3x4 is 12, what is the missing number?
__x3=12
6
Objective and
Strategies
Concrete Pictorial Abstract
Ten times bigger
Language of ten
times bigger
must be well
modelled and
understood
Dienes
Ruler mm cm
Possible misconception: move the decimal point
Encourage children to keep the decimal point stationary
and move the digits. Use Zero the Hero.
What is the relationship between the following:
2x3, 2x30, 20x3, 20x3x10
Missing numbers
__x10=15
5x__=15
7
Objective and
Strategies
Concrete Pictorial Abstract
Multiplying by
10,100 and 1000
5x1=5
5x10=50
3x1=3
3x100=300
Place value chart
Equivalent calculations
98x5=98x10÷2
Measures and money problems
Missing number questions
Multiplication of
2-digit numbers
with partitioning
(no regrouping)
13x3=39 13x3=39 3x12
10 and 2 make 12
3x2=6
3x10=30
30+6=36
Missing values on grid
8
Objective and
Strategies
Concrete Pictorial Abstract
Multiplication of
2-digit numbers
with partitioning
(regrouping)
3x25
20 and 5 make 25
3x5=15
3x20=60
AND
15=10 and 5
SO
60+10=70
70+5=75
Grid method Use Base 10
4 rows of 13
24x3=72 Start with multiplying by 1-digit numbers and showing
clear addition alongside the grid.
Multiply by a 2-digit number
Missing digits
9
Objective and
Strategies
Concrete Pictorial Abstract
Short
multiplication
It is important here that
children always multiply
the ones first and note
down their answer
followed by the tens
which they also note
down.
Bar modelling and umber lines can support learners when solving
problems with multiplication alongside the formal written methods.
Start with long multiplication, reminding the children
about lining up their numbers clearly in columns.
If it helps, children can write out what they are solving next
to their answer.
This moves to the more compact method.
1
SIJS Addition & Subtraction Policy Addition
Objective and Strategies
Concrete Pictorial Abstract
Combining two parts to make a whole: part-whole model
Use cubes to add two numbers together as a group or in a bar. Then recount all using
one-to-one correspondence. (The colours of the cubes are important for
correspondence)
Pupils could place ten on top of the whole as well as writing it down. The parts could
also be written alongside the concrete representation.
Use pictures to add two numbers together in a group or in a bar:
3 + 2 = 5 Use the part-part whole diagram as shown above to move into the abstract.
10 = 6 + 4 10 – 6 = 4 10 – 4 = 6 10 = 4 + 6 10 = ? + 6 10 - ? = 4
etc
Use starters such as: How many more to
make….?
Starting at the bigger number and counting on
Using counters then beads, start with the larger number and then count on the smaller number 1 by 1 to find the answer.
12 + 5 = 17 (on a marked number line)
Start at the larger number on the number line and count on in ones or in one jump to find the answer (blank number line with increments) Use spider to jump in 10s Use Frog to jump in 1s
5 + 12 = 17 Hold the larger number in your head and count on the smaller number to find your answer. 12, 13, 14, 15, 16, 17 Spider to jump on in 10s Frog to jump on in 1s 10s 1s
Make Ten strategy
6 + 5 = 11
Start with the bigger number and use the smaller number to make 10
Use pictures or a number line. Regroup or partition the smaller number to make 10. Using a ten frame:
7 + 4 =11 If I am at seven, how many more do I need to make 10? And how many more do I add on? (blank number line)
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2
Regrouping (exchanging) to make 10
The colours of the beads on the bead string make it clear how many more need to be added to make ten.
Use multilink/counters on a ten frame:
9 + 5 = 14
This is a concrete/pictorial skill that will support the make ten strategy and column addition.
Adding multiples of 10
Using the vocabulary of 1 ten, 2 tens , 3 tens etc alongside 10, 20, 30 is important as pupils need to understand that it is a ten and not a one that is being added.
50 = 30 + 20
Using dienes equipment e.g. 34 + 20 = 54 INSERT PHOTO
Introduce the kangaroo who jumps in big jumps of multiples of 10, 100 etc on a number line:
3 tens + 5 tens = ____tens 30 + 50 = ______ Use a hundred square with spider counting up and down in 10s Using place value chart with place value counters to see how the tens column changes each time a multiple of 10 is added
50 + 20 = 70 Children count up in tens 50,60,70 or may recognise their number bonds 5 + 2 = 7 so 50 + 20 = 70
Using numbers up flip folders: What is 1 more than …? What is 12 more than…?
Adding near multiples of 10 by adjusting (+9, 19, 29; +1, +11, +29 etc)
Using dienes equipment as above changing the tens to ones to show the adjusting process 30 + 19 = 49 30 + 20 = 50 and adjust to give one back
Using a number line: The Wave (+ 9, 19, + 8 etc)
The Seagull ( + 1, 11, 21 etc)
Children to mentally add near multiples of 10 by adding the too much and giving one back e.g 23 + 9 45 + 19 44 + 29 or adding tens and adding one more: e.g – 44 + 11 32 + 21
3
Adding three single digit numbers
4 + 7 + 6 = 17 Put 4 and 6 together to make 10. Add on 7
The first bead string shows 4, 7 and 6. The colours of the bead string show that it makes more than ten. The second bead string shows 4,6 and then 7. The final bead string shows how they have now been put together to find the total.
Add together three groups of objects. Draw a picture to recombine the groups to make 10. Use 3 ten frames with counters to represent each amount and then combine:
Combine the two numbers that make 10 and then add on the remaining amount:
Include missing number questions:
4 + ? + 6 = 17
How many more to make…?
Place value addition (Partitioning)
Partition with cubes, dienes, beadstring, counters, place value counters.
Taking one number and partitioning the other. 22 + 17 = 39 “No work calculation”
22 + 17 = 39 Use informal jottings:
22 + 17
30 9
30 + 9 = 39
Using known facts (I know….so…)
Number bonds, Doubles, Near doubles…
Using dienes equipment: If 3 + 4 = 7 What is 0.3 + 0.4?
4
Column method – regrouping (carrying)
Using dienes equipment on a place value chart:
Make both numbers on a place value grid: 146 + 527
(carry row) Add up the units and exchange 10 ones for one 10
(carry row)
Add up the rest of the columns, exchanging the 10 counters from one column for the next place value column until every column has been added. As children move on to decimals, money and decimal place value counters can be used to support learning.
Children can draw a pictorial represntation of the columns and place value counters to further support their learning and understanding
The carry row should be above for consistency within written method
Expanded method:
Moving on to the compact method:
Need examples with carry row
5
Subtraction
Objective and Strategies
Concrete Pictorial Abstract
Taking away ones When this is first introduced, the concrete representation should be based upon the diagram. Real objects should be placed on top of the images as one-to-one correspondence progressing to representing the group of ten with tens rod and ones with ones cubes.
Use a variety of objects, counters, cubes etc to show how objects can be
taken away:
6 - 2 =4
Cross out drawn objects to show what has been taken away: 8 – 7 = 1 9 – 4 = 5 10 – 5 = 5
18 – 3 = 15
8 – 2 = 6
Counting back
Make the larger number in your subtraction. Use a variety of objects, cubes, counters etc and move them
away from the group as you take them away counting backwards as you go.
Use a bead string to move the beads along as you count backwards in ones.
13- 4 = 9
Count back on a number line or a number square: Frog counting back in ones (number line with increments and/or labelled) (number square) Start at the bigger number and count back the smaller numbers showing the jumps on the number line: (Kangaroo – count back in 10s; Frog – count back in 1’s) Using a number square:
Put 13 in your head, count back 4. What number are you at?
Record on a blank
number line
6
Find the difference
Compare amounts and objects to find the difference:
Use cubes to build towers or make bars to find the difference
Use basic bar models with items to find the difference
Draw bars to find the difference:
Count on to find the difference:
Hannah has 23 sandwiches, Helen has 15 sandwiches.
Find the difference between the number of sandwiches.
Part part whole model
Link to addition – use the part whole model to help explain the inverse between addition and subtraction.
If 10 is the whole and 6 is one of the
parts. What is the other part? 10 – 6 =
Use a pictorial representation of objects to show the part-part-whole model.
Move to using numbers within the part whole model:
Subtracting 10s
Use base 10 materials
Use spider – spider lives up in the ceiling and come down and goes back up in a straight line. Counting in 10s.
34 - 10 =
7
Making 10 Bridging
Make 14 on the ten frame. Take
away the four first to make 10 and then take away five more so you
have taken away 9. You are left
with the answer of 5.
14 – 8 = (14 – 4 – 4)
Start at 13. Take away 3 to reach 10. Then take away the remaining 4 so you have taken away 7 altogether. You have reached your
answer.
Moving on to using number lines with increments but no labelled.
16 – 8=
How many do we take off to reach the next 10? How many do we have left to take off?
Subtracting tens and adding extra ones Pupils must be taught to round the numbers that is being subtracted. Pupils will develop a sense of efficiency with this method, beginning to identify when this method is more efficient that
subtracting tens and then ones.
“The wave” 53 – 17 = 36
53 – 17 = 36 Round 17 to 20 53-20 = 33 20 – 17 = 3(number
bonds) 33+3 = 36 (we add because we took an extra 3 away when we subtracted 20 instead of 17)
8
Subtracting multiples of ten
Using the vocabulary of 1 ten, 2
tens, 3 tens etc alongside 10,20,30 is important as pupils need to
understand that it is a ten not a
one that Is being taken away.
Use beads aswell
5 tens – 2 tens = ___tens 50 – 20 = ____
Using a hundred square:
32 – 10 = 22 Look at the number
of tens in the largest number. Count back in tens to subtract the smaller number. 30,20. Add on the number of ones that we originally had. Counting back in 10s or 100s from any starting point 53,43,33…. 540, 440,340….
Counting back in multiples of ten and one hundred
Removing one group of 10 each
time
Kangaroo jumps back in 10s
Subtracting near multiples of ten and adjusting
The wave ( -9, -8 etc – take too much and give some back)
The seagull (-11, -12 etc – take 10 and take some more)
9
Adding using compensation rounding and adjustment
54,128 + 9987 54128 + 10, 000- 13 = 64,218 – 13 Highlight that the calculation can be done in another order:
Using near doubles: e.g
70 – 60 70 – 70 = 0 so add on 10 more is 10
Column method without regrouping
Use Base 10 to make the bigger
number then take the smaller number away.
Show how you partition numbers to subtract. Again make the larger
number first.
Draw the Base 10 or place value counters alongside the written calculation to help to show working.
Expanded method:
This will lead to a clear compact written method:
10s 1s
10
Column method with regrouping
Use Base 10 to start with before
moving on to place value counters. Start with one exchange before
moving onto subtractions with 2
exchanges. Make the larger number with the place value
counters
Make the larger number with the place value counters
Start with the ones, can I take away 8 from 4 easily? I need to
exchange one of my tens for ten
ones.
Now I can subtract my ones.
Now look at the tens, can I take
away 8 tens easily? I need to exchange one hundred for ten
Draw the counters onto a place value grid and show what you have taken away by crossing the counters out as well as clearly showing the exchanges you make.
When confident, children can find their own way to record the exchange/regrouping
Children can start their formal written method by
partitioning the number into clear place value columns. Expanded method:
Compact method:
This will lead to an understanding of subtracting any number including
decimals
11
tens.
Now I can take away eight tens
and complete my subtraction
Show children how the concrete method links to the written method
alongside your working. Cross out the numbers when exchanging and
show where we write our new amount.