Number · Standard form
Chapter 1 · 4
The idea
Writing numbers in standard form
Why standard form fixes exactly one non-zero digit before the point, what the power of 10 really counts, why negative powers mean small (not negative), and how to compare sizes at a glance.
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Number · Standard form
Writing numbers in standard form
Why standard form fixes exactly one non-zero digit before the point, what the power of 10 really counts, why negative powers mean small (not negative), and how to compare sizes at a glance.
Why it works
One number, one costume
The Sun's mass is about kg — written like that, nobody can even read it, let alone compare it with anything. Science needed a costume that shows a number's size at a glance, and standard form is it:: start at and push the point seven places right.
Why a sits between 1 and 10
Without that rule the same number has many costumes — , and are all equal — and none of them could be compared at a glance. Forcing one non-zero digit before the point makes the form unique, so is not standard form: trade a factor of 10 from the 45 into the power, . (Coefficient down ÷10 ⇒ power up +1, and vice versa — the trade must balance.)Keep reading — free
The rest of the explanation, plus 2 worked examples you step through move by move.
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