MemoryMentor's Blog

For example many people would use ? (Pi) rounded to 3, or 3.14 which is all well and good for theoretical purposes, but let’s try it out when calculating the circumference of Mars when a space ship is going to land on it.

Google search tells me the radius of Mars is 3397 kilometres, or 3,397,000 metres.

To calculate the circumference of Mars, we use the formula

C = 2 X ? X R

Where C is the circumference

R is the radius.

Let’s use these values of Pi as our radius:

1. 3
2. 3.1
3. 3.14
4. 3.142
5. 3.141592653

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1. C = 2 X 3 X 3397000                          20382000 metres
2. C = 2 X 3.1 X 3397000                       21061400 metres
3. C = 2 X 3.14 X 3397000                     21333160 metres
4. C = 2 X 3.142 X 3397000                   21346748 metres
5. C = 2 X 3.141592653 X 3397000       21343980.484482 metres

Now, imagine if you were on a space mission and you were plotting where to the land the space craft, but accidentally the value of 3 was used for Pi rather than the more accurate one!

If we take the most accurate one and subtract the least accurate result from it, we get

961980.484482.

That equates to over 961 KILOMETRES off target!

Sometimes rounding mightn’t always be the best option!

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