How many significant figures does 507.2m have?

4

Explanation:

To find the significant digits we have few methods.

METHOD 1--Count from left to right

A number that has a decimal point, count digits from the first number from the left that isn't zero.

METHOD 2--Count from right to left

A number that doesn't have a decimal point, count digits from the first number from the right that isn't zero.

It is obvious that 507.2 has a decimal point, so we count from left which we will start with 5.

5, 0, 7, 2

There are 4 digits.

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