3.7 x 10³ is the scientific notation
3700 is its standard form
3,700 x 1000 = 3,700,000
3.7 x 10⁶ is its scientific notation. Choice C.
We can only add the number of zeros there are in the exponent.
3.7 x 10³ ; there are 3 zeros in 1,000
3.7 x 10³ ⁺ ³ = 3.7 x 10⁶