Every ten minutes during sunset, the sky changes to a new color. How many colors did the sky turn over the two hours of a long summer sunset if each hour is sixty minutes long?
At 60 minutes per hour, the sunset was 2 * 60 = <<2*60=120>>120 minutes long.
The sky changes color every 10 minutes, so it turned 120 / 10 = <<120/10=12>>12 colors over the summer sunset.
#### 12