Hello Littlelamb!
The answer you're looking for is [tex]2.12 * 10^{-3} [/tex]
[NOTE: MAKE SURE YOU DO 10^-3 TO INDICATE THAT IT IS AN EXPONENT! More often than not the exponent wouldn't come through as an exponent. Example: [tex] x^{3} [/tex] would look like x3. To signify that it is an exponent you do x(^)3.]
As always, it'll be multiplied by 10. It's evident that the power 10 will be raised to would be the third power given that there is three zeroes. It's also evident that it'll be a negative power since we are dealing with a number/decimal less than one. What solidify this is the fact that we have to move the decimal point to the left three times (moving a decimal point left leads to the exponent being negative and the number of times you move the decimal point is the exponent number. In this case it's -3) in order to make a digit, that isn't zero, in front of the decimal point. 0.00212 -> 0.0212 (1) -> 0.212 (2) -> 2.12 (3)
Therefore, 2.12 * 10^-3
