Which number is bigger 6.4 or 6.004?

To determine which number is bigger, we compare the digits place by place. In this case, the first digit after the decimal point is the deciding factor. In 6.4, the digit after the decimal point is 4, while in 6.004, the digit after the decimal point is 0. Since 4 is greater than 0, 6.4 is bigger than 6.004.