Standard Index form

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Standard Index form
Objective To convert numbers into standard index
form
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Why is this number very difficult to use?
999,999,999,999,999,999,999,999,999,999
Too big to read
Too large to comprehend
Too large for calculator
To get around using numbers this large, we use
standard index form.
3
We can round it up to 100,000,000,000,000,000,000
,000,000,000
So at the very least we can describe it as 1 with
29 noughts.
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Lets investigate!
Converting large numbers
We can break numbers into parts to make it
easier, e.g. 80 8 x 10 and 800 8 x 100
800,000,000,000 8 x 100,000,000,000
And 100, 000,000,000 1011
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Try it out!
How can we convert 30,000 into standard index
form?
Break into easier parts
The number is now easier to use
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Now its your turn
Copy down the following numbers, and convert them
into standard index form.

• 500
• 4000
• 60,000
• 900,000
• 7000,000

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One of the most important rules for writing
numbers in standard index form is
For example, 39 x 106 does have a value but its
not written in standard index form. The first
number, 39, is greater than 10.
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How could we convert 350,000,000 into standard
index form?
Again, we can break the number into smaller, more
manageable parts.
350,000,000 3.5 x 100,000,000
100,000,000 108
350,000,000 3.5 x 108 in standard index form
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Try it out!
How can we convert 67,000 into standard index
form?
67,000 6.7 x 10,000
10,000 104
67,000 6.7 x 104 in standard index form
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Now its your turn
Copy out the following numbers and convert them
into standard index form.

• 940
• 8,600
• 34, 000
• 570,000
• 1,200,000

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Can you find a quick method of converting numbers
to standard form?
For example, Converting 45,000,000,000 to
standard form
Place a decimal point after the first digit
4.5000000000
Count the number of digits after the decimal
point.
This is our index number (our power of 10)