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Revision:Standard Form
From The Student RoomTSR Wiki > Study Help > Subjects and Revision > Revision Notes > Mathematics > Standard Form
IntroductionStandard form is a method of writing down very large or very small numbers easily. The method relies on using powers of ten to shorten the numbers. Consider the number
This idea can be used to write even larger numbers down easily in standard form. Small numbers can also be written in standard form. However, instead of the index being positive (in the above example, the index was 3), it will be negative. The rules when writing a number in standard form is that first you write down a number between 1 and 10, then you write × 10(a number).
Operations in Standard FormAddition and Subtraction in Standard FormWhen adding two numbers in standard form, it helps to have them both with the index of 10, so we remove one from standard form. Perform the operation (taking out the index of 10 as a common factor) and then convert back into standard form. Consider this example, adding First we convert to the same exponent (I personally prefer to use the lower exponent)
Take out the common factor of
This isn't in standard form since 99 isn't between 1 and 10, therefore we put it into standard form
We follow an identical method for subtraction Multiplication in Standard FormDivision in Standard FormExponentiation in Standard FormCommentsMore areas need to be covered - including converting to decimal standard form (eg 44511.7 = 4.45117 x104), negative powers in standard form, adding and subtracting numbers in standard form and multiplying and dividing numbers in standard form. |










Therefore we can write
which is writing it in standard form.





