Maths

Maths


http://stjomathszone.blogspot.co.nz/ Great blog with videos and websites to help the children's learning

Our Key Strategies for Addition and Subtraction
Strategy
Example
Place Value (Addition)
Splitting the numbers into parts
234 + 657 = 891
200 + 600 = 800
30 + 50 = 80
4 + 7 = 11
800 + 80 + 11 = 891

Place Value (Subtraction)
Splitting the numbers into parts using the big number first
89 – 36 = 53
89 – 30 = 59
59 – 6 = 53

Rounding and Compensating (Addition)
Adding a little bit on to make a tidy number then taking that little bit off at the end
145 + 28 = 173
28 + 2 = 30
145 + 30 = 175
175 – 2 = 173

Rounding and Compensating (Subtraction)
Adding a little bit on to make a tidy number then adding that little bit more on at the end to make up for taking too much off
175 – 99 = 75
99 + 1 = 100
175 – 100 = 75
75 + 1 = 75

Equal Additions (Subtraction)
Adding a small bit to the second number to make it a tidy number, then adding the same amount to the other number to adjust the adding
376 – 48 =
48 + 2 = 50      376 + 2 = 378
378 – 50 = 328

Reversibility (Subtraction)
Making a subtraction problem into an addition problem to make it easier to solve
33 – 26 = 7
26 + _ = 33
26 + 7 = 33



Addition and Subtraction Strategy video links:
Decimal Place Value video links:

Perimeter and Area video links:
http://www.educreations.com/lesson/view/area-of-irregular-shapes/22962511/?ref=app

Multiplication Strategies I can use:
Strategy
Example
Using my 5 times tables to work out 6,7 and 8 times tables

8 × 7 =
8 × 5 = 40
8 × 2 = 16
40 + 16 = 56
Place Value (Basic Mult)
Splitting the numbers into parts
24 × 5 =
20 × 5 = 100
4 × 5 = 20
100 + 20 = 120
Place Value (Harder Mult)
Splitting the numbers into parts
35 × 63 =
30 × 60 = 1800
30 × 3 = 90
5 × 60 = 300
5 × 3 = 15
1800 + 300 = 2100 + 90 = 2190 + 15 = 2205
Rounding and Compensating (Mult)
Adding more groups on to make a tidy number then taking off the groups at the end
37 × 6 =
(add 3 groups on)
40 × 6 = 240
240 – (3×6=18) = 222
Doubling and Halving (Mult)
You look for one of the numbers that when doubled or halved will give you an easy problem to solve.
42 × 20 =
Halve 20 = 10
Double 42 = 84
So now solve 84 × 10 = 840

Division Strategies I can use:
Strategy
Example
Using my times tables to work out basic division facts
8 × 7 = 56
so
56 ÷ 8 = 7
Reversibility
Change the division problem to a multiplication problem
42 ÷ 7 =
7 × ____ = 42
so 7 × 6 = 42
Place Value
Splitting the numbers into parts
96 ÷ 8 =
We think of our 8 times (times by 10) tables to help us split the numbers e.g. 80, 160.
80 ÷ 8 = 10
Then we work out how much is left over 96 - 80 = 16 so
16 ÷ 8 = 2
10 + 2 = 12
Halving and halving
Halving both the numbers until you can find ÷an easy solution.
112 ÷ 8 = ?       112 ÷ 2 = 56       8 ÷ 2 = 4
56 ÷ 4 = ?         56 ÷ 2 = 28         4 ÷ 2 = 2
28 ÷ 2 = 14
Rounding and Compensating
Adding more groups on to make a tidy number then taking off the groups at the end
68 ÷ 4 =
we round it up to 80 as that is in the 4 times tables.
80 ÷ 4 = 20
20 - (12÷4= 3) = 20-3 = 17
Long Division

Good site for maths videos and activities - https://www.khanacademy.org/

Multiplication Strategy video links:
http://www.educreations.com/lesson/view/6-7-8-times-tables-from-known-times-tables/23151903/?ref=app


http://www.mathematicshed.com/index.html - good engaging maths site

These are some good measurement games to play:

These are some good Geometry Games for you to play: 


Click on these links for games for you to practice your multiplication

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