What is a quarter of 6?

1½, or 1.5

"One quarter" means to divide by 4, but 6 isn't a multiple of 4 so the answer includes a remainder. In common practice, the remainder part of a division is written as a fraction whose numerator is the remainder itself and the denominator is the divisor.

In this case 6 is divisible by 4 one time with 2 left over, so the answer is 1 and 2/4. Reduced to lowest terms 2/4 is 1/2, which can also be expressed as the decimal 0.5