Page 95 - Knowledge Organiser Yr8 24-25

Knowledge Base: Mathematics TOPIC 14: Numerical Calculations Year 8 | Autumn Term 1
By the end of this topic you should be able to:
• Use the correct order of operations
• Round numbers (using place value and decimal places)
• Use written methods of addition and subtraction
• Add and subtract decimals
• Use mental methods for multiplication and division
• Use written methods for multiplication
• Use written methods for division
to multiply and divide with decimals
Decimal
A number which has digits after the decimal point
3.25 and 4.13 are decimal numbers
Language
Meaning
Example
Round
To write a number as a near approximation
153 = 150 to the nearest 10 153 = 200 to the nearest 100
Partitioning
Splitting a number into parts to make a mental calculation easier
27 + 18 = 27 + 10 + 8 = 37 + 8 = 45
Compensation
Rounding one of the numbers and then adjusting the final answer to your sum
27 + 18 = 27 + 20 – 2 = 47 – 2 = 45
Inverse Operation
A second operation that undoes the effect of the first operation
-5 is the inverse of +5 ÷4 is the inverse of ×4
Sum
Difference
Product
Divisor
Short Division Long Division
Long Multiplication
The sum of 5 and 6 is 11
The difference between 9 and 3 is 6 The product of 3 and 4 is 12
In 10 ÷ 5 = 2, 2 is the divisor
Another word for add
Another word for subtract
Another word for multiplication
The number you divide by
A way of setting out workings when dividing by a single digit number A way of setting out workings when dividing by a multi-digit number A way of setting out workings when multiplying
BIDMAS Bracket Indices
Division or Multiplication (whichever comes first) Addition or Subtraction (whichever comes first)
Worked examples
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