16. (15 points) Uncle Li contracted 12 mu of paddy fields, with a yield of 660 kilograms per mu. Aunt Lin contracted 2 mu less of paddy fields than Uncle Li, and the total yield of rice is 420 kilograms less than Uncle Li's. Questions:
(1) What is Uncle Li's total yield of rice in kilograms?
(2) How much less is Uncle Li's yield per mu compared to Aunt Lin's?
【Analysis】(1) Yield per mu $\times$ number of mu $=$ total yield, according to this, substitute the data to solve;
(2) First, calculate the total yield and total mu of Aunt Lin's rice, then according to the meaning of division, the solution can be obtained.
【Solution】Solution: (1) $660 \times 12=7920$ (kg);
Answer: Uncle Li's total rice yield is 7920 kg.
(2) $(7920-420) \div 10$
$$
\begin{array}{l}
=7500 \div 10 \\
=750 \text { (kg) } \\
750-660=90 \text { (kg); }
\end{array}
$$

Answer: Uncle Li's rice yield per mu is 90 kg less than Aunt Lin's.
【Comment】This problem mainly examines the relationship between yield per mu, number of mu, and total yield.