A quantitative observation is not necessarily more useful than a non-quantitative one. However, quantitative observations do allow one to find trends.
(a), the sun rising is a non-quantitative observation.
(b), knowledge of the numerical relationship between the weight on the Moon and on Earth, is a quantitative observation.
(c), watching ice float on water does not involve a measurement; therefore, it must be a qualitative observation.
(d) the fact that we know that the water pump won’t work for depths more than 34 feet makes it quantitative. Again, seeing numbers is a giveaway that it’s a quantitative observation. Quantitative is where you deal with numbers.