Multiple choice Represent 15 million in standard index form. 1.5 × 107 1.5 × 106 1.5 × 105 1.5 × 104 Reveal answer Fill a bubble to check yourself A Correct answer Explanation 15 million = 15,000,000 = 1.5 × 10,000,000 = 1.5 × 10^7. The decimal moves 7 places left to put one digit before it.