lesson

Updated 1 month ago Β· 5 views
Imagine multiplying 200,000 by 3,000,000 β counting all those zeros by hand is slow and easy to mess up.
Scientific notation gives us a shortcut: write numbers as a front number times a power of 10, like 2Γ105.
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How do we multiply two of these numbers together in two quick steps?
The Two-Step Rule
First, multiply the coefficients (the front numbers). Then, add the exponents (the small power numbers on the tens).
Why do we add exponents? Because 102Γ103=(10Γ10)Γ(10Γ10Γ10)=105, which is just 2+3=5 tens.
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Let's test this rule on (2Γ103)Γ(3Γ104).
(2Γ3)Γ(103Γ104)=6Γ103+4=6Γ107
What happens if multiplying the front numbers gives a number that is 10 or bigger?
Fixing the Front Number
In scientific notation, the front number must always stay between 1 and 10 (never 10 or larger).