This problem shows an important Python 3 feature: / always returns a float. 6 / 3 gives 2.0, not 2.
// returns an integer (floor division). 7 // 3 gives 2.
Use // when you need whole numbers. Use / when you need precision.
Be careful with negative numbers: -7 // 3 is -3, not -2. Floor division rounds toward negative infinity, not toward zero. Knowing both operators saves you from writing int(a / b) when a // b does the job cleaner.