Let's list the choices.
1.5x10^3
1.4x10-1
2x10 ^3
1.4 x 10-2
First, you look at the exponent of 10. The positive exponent of 10 will always be larger than the negative because the decimal point moves to the right, increasing its value. The greatest is 10^3. Between these two, the greater one is 2 followed by 1.5.
For the negative exponents of 10, 10^-2 is lesser than 10^-1.
Thus, if you arrange from least to greatest:
1.4 x 10-2 < 1.4x10-1 < 1.5x10 ^ 3 < 2x10 ^3
