Negative exponent We know that a−n = 1 / an when a ≠ 0. So 10−1 = 1/10 = 0.1, 10−2 = 0.01, 2−3 = 1/8. Standard form A positive number in standard form is k × 10n where 1 ≤ k < 10 and n is an integer.4500 = 4.5 × 10³. 0.0032 = 3.2 × 10−3. 6.02 × 10²³ is already in standard form.