Are there any built-in functions in PHP as there are in Excel?

Question

For example ROUND(value, position after decimal point)

Answer 1

Yes, PHP comes with many built-in functions, here is a list of all of them:
http://php.net/manual/en/indexes.functions.php

The one that matches your example would be round():
http://php.net/manual/en/function.round.php

So for example:
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$pi = 3.14159;
echo round(pi, 3);
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Would output 3.142