Year 3 and 4 Calculations
Maths Information Session
• Welcome
• Multiplication
• Subtraction
• Division
• Addition
Multiplication
• Arrays
e.g. 5 x 6
• Partitioning
e.g. 5 x 13
Multiplication
• Grid Method
Example
4 x 162 =
•
•
•
•
•
•
•
Success Criteria
Estimate
Draw grid - what size?
Partition each number
Multiply the numbers
Put on correct zeros
Add vertical boxes in
columns
• Check against
estimate
Multiplication
• Now its your turn
1. 153 x 5 =
2. 5 x 16 =
3. 5 x 7 =
• Have a go at one or all three calculations
using the methods the children showed
you.
Subtraction
• Number Line
Example
140 - 67 =
Subtraction
• Column Subtraction
Example
143 - 69=
Success Criteria
• Put digit in correct column
• Line up the decimal point
• Write the - sign
• Put the decimal point in
answer box
• Copy numbers correctly
• Start at right
• Borrow from the left if you
need to
• Watch out for the zeros!
Subtraction
•
Have a go at these using either of the methods you have
been shown.
1.
2.
3.
130 -77 =
145 - 68 =
46 – 34 =
Success Criteria
•
Put digit in correct column
•
Line up the decimal point
•
Write the - sign
•
Put the decimal point in answer box
•
Copy numbers correctly
•
Start at right
•
Borrow from the left if you need to
•
Watch out for the zeros!
Division
• Grouping
e.g. 32 ÷ 5 =
Division
• Number Line
Example
127 ÷ 4 =
• Alex over to you!
Division
• Chunking
Example
127 ÷ 4 =
Chunking Success!
• Work out multiples of the
number you are dividing by
• e.g. 10x, 5x, 20x, 30x,
• Subtract the largest multiple
possible
• Record in brackets which
multiple you are subtracting
• Continue until the remainder
is smaller than the number
you are dividing by
• Add up how many multiples
you have subtracted
• Record your answer e.g. 78
r9
Division
• Bus Stop
Example
127 ÷ 4 =
Division
•
Three examples for you
(Think which of the
methods you would use to
solve them)
1.
2.
3.
134 ÷ 4 =
43 ÷ 6 =
691 ÷ 4 =
Remember Chunking Success!
• Work out multiples of the
number you are dividing by
• e.g. 10x, 5x, 20x, 30x,
• Subtract the largest multiple
possible
• Record in brackets which
multiple you are subtracting
• Continue until the remainder
is smaller than the number
you are dividing by
• Add up how many multiples
you have subtracted
• Record your answer e.g. 78
r9
Addition
• Number Line Addition
e.g. 64 + 89 =
• Partitioning Addition
Addition
• Column Addition
e.g. 109 + 17 =