4. (Ancient Indian problem 3-4th century AD). Of the four sacrificial donors, the second gave twice as many coins as the first, the third three times as many as the second, the fourth four times as many as the third, and all together gave 132 coins. How many did the first give?
4. The first method of solving. By analyzing the condition of the problem, one can conclude that the number of coins given by the first person will not be more than 10. We will then refine this number through trial and error. Let's try the number 5.

$$
5+5 \times 2+5 \times 2 \times 3+5 \times 2 \times 3 \times 4=5+10+30+120=165
$$

Since the obtained number is greater than the given number, we made a mistake in our choice. Let's take the number 4. Checking shows that it satisfies the conditions of the problem.

The second method of solving. When solving this problem, it is useful to make a drawing, representing each number as a segment. This way, it will be immediately clear that 33 identical segments equal 132. From this, it is easy to determine the amount of money given by the first donor.

The third method of solving. This problem can also be solved using an equation. For this, let $x$ be the amount of money given by the first donor. Based on the condition, the following equation can be formed:

$$
\begin{gathered}
x+2 x+(2 x) \times 3+(2 x \times 3) \times 4=132 \\
x+2 x+6 x+24 x=132,33 x=132, x=4
\end{gathered}
$$

Answer: the first person gave four coins.