What is direct proportion?
A direct proportion is used to show how quantities and amounts are related related each other. If y is proportional to x, we can write this as y=kx.
Convert between currency
Different countries have different currencies. To convert from pounds to another currency, exchange rates are used. An exchange rate is how much one pound is equal to in their currency; exchange rates are constantly changing.
Foreign currency= British currency x exchange rate.
Scale factors
When things are too large to represent on a diagram, scale factors are used. These are numbers which scale or multiply a quantity. Scale factors are used to calculate smaller measurements that are in direct proportion with the original. For example, 1 centimetre on a map is equal to 1 metre in real life. In this case, the scale factor is 100.
Similar shapes
In fact, they aren't even similar; they're exactly the same. If a shape can become another using resizing, then they are similar. If they are similar but do not use resizing, this is called congruent. Sometimes, it is hard to tell if shapes are similar because it may need to be turned, flipped or slided. The fancy names are:
Rotation: to turn.
Reflection: to flip.
Translation: to slide.
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Maths Revision
RandomMy funny and well-explained KS3 Maths Revision guide, derived from Bitesize. Still in progress, as I learn the nightmare called Maths by myself.
