To write 6.4 as a fraction, we need to consider the decimal part. As 6.4 has one decimal place, we can write it as the fraction 6.4/10. To simplify this fraction, we can divide both the numerator and denominator by their greatest common divisor, which is 0.8. This gives us 6.4/10 = 64/100. Therefore, 6.4 can be written as the fraction 64/100.
