INVERSE - the word 'inverse' means opposite
The inverse of adding is subtracting
The inverse of subtracting is adding
The inverse of multiplying is dividng
The inverse of dividing is multiplying
Order of Operations (BIDMAS)
-10 -8 -6 -4 -2 0
All numbers above 0 are positive numbers
All numbers below 0 are negative numbers
0 is neither positive nor negative.
Two Signs Together - positive and negative
2 x + = positive 2 x - = positive
+ and - = negative
- and + = negative
1 all whole numbers divide by 1
2 if the number ends in 0,2,4,6 or 8
3 add the digits - will divide by 3
5 ends in 0 or 5
10 ends in 0
Sequences are very important in maths. We can often make sense of puzzles by looking for sequences or patterns.
Each number in a sequence is called a term. The rule that connects the terms is called the term-to-term rule. eg. 4,7,10,13,16... The first term is 4. The term-to-term rule is that we 'add 3'. if you know the first term and the term-to-term rule, you can generate as many teerms as you like.
An ascending sequence is one that goes up. A descending sequence is one which goes down. An infinite sequence is one which goes on for ever. A finite sequence is one which has an end. Terms of a sequence which are next to each other, are called consecutive.
Algebra + Substitution
Remember, algebra is substitung a letter for a number that we dont know yet. We follow the same rules for algebra as we do for numbers. To decide the order in which to do things, we still use BIDMAS. We can use the concept of 'undoing' to rearrange algebra. Sometimes we rearrange algebra even when it doesnt get us to a numerical answer.
Substitution is where we find out the value of a letter in algebra.
Area + Perimeter
When we find the perimeter of a shape, we measure all the way outside. The word 'perimeter' comes from the greek 'peri' which means around, and 'meter' which means 'to measure'.
The space inside a 2D shape can be measured in cm2, m2, mm2
Calculated using formulae, or occasionally by counting squares.
AREA OF A RECTANGLE = length x width
AREA OF A TRIANGLE = base x height
2 (height must be perpendicular to base)
Equivalent fractions are fractions that are the same amount but use differnt numbers. 1/2 = 4/8 = 8/16 = 16/32 etc etc
A pair of equivalent fractions can be found where both the numerators and denominators are multiplied by the same number.