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secondary 4 | E Maths
2 Answers Below
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i dont understand why am i wrong
if i multiply 10^-2 i have to move to the left hand side by 2 and then my ans wld be 0.0227x10^6
Date Posted: 2 years ago
Views: 214
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done
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clear
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By expanding it out it like this it should be easier for you to visualise it, hope it helps! :)
Date Posted:
2 years ago
Thankyou !!
Your thinking is conceptually wrong.
If you multiply by 10⁻² , that 0.227 needs to be divided by 10⁻² (equivalent to × 100) , in order to keep the entire amount the same. Otherwise, you are actually going to end up with a result that is 1/100 of the actual.
How it works : 2.27 × 10⁸ km
= 2.27 × 10⁸ km × 10⁻² ÷ 10⁻²
= 2.27 ÷ 10⁻² × 10⁸ km × 10⁻²
= 2.27 ÷ 1/100 × 10⁸⁻² km
= 2.27 × 100/1 × 10⁶ km
= 227 × 10⁶ km
= 227 million km (since 1 million = 10⁶)
k = 227
If you multiply by 10⁻² , that 0.227 needs to be divided by 10⁻² (equivalent to × 100) , in order to keep the entire amount the same. Otherwise, you are actually going to end up with a result that is 1/100 of the actual.
How it works : 2.27 × 10⁸ km
= 2.27 × 10⁸ km × 10⁻² ÷ 10⁻²
= 2.27 ÷ 10⁻² × 10⁸ km × 10⁻²
= 2.27 ÷ 1/100 × 10⁸⁻² km
= 2.27 × 100/1 × 10⁶ km
= 227 × 10⁶ km
= 227 million km (since 1 million = 10⁶)
k = 227
Typo : it should be 'that 2.27' instead of 'that 0.227'
Alternative working : (I prefer this one, it's much clearer)
2.27 × 10⁸
= 2.27 × 10² × 10⁶
= 2.27 × 100 × 10⁶
= 227 × 10⁶
= 227 million
k = 227
Alternative working : (I prefer this one, it's much clearer)
2.27 × 10⁸
= 2.27 × 10² × 10⁶
= 2.27 × 100 × 10⁶
= 227 × 10⁶
= 227 million
k = 227
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