Solution: understand the topic as follows: half of a half watermelon is less than half of the whole pile. Let the whole heap be numbered X.

Then, (0.25+0.5)=0.5x, and x= 1.5.

Provide a few more questions for your reference:

1. Monkeys go to Taoyuan to eat peaches. The first group of monkeys ate more than half of the peach garden, the second group ate more than half of the peach garden, the third group ate more than half of the peach garden, and finally there were 100 peaches. How many peaches do you want?

Answer and hint: There were 807 peaches in Taoyuan.

Start with the second surplus (or ask yourself: the final surplus is 100, 100. How to express it with words containing "half" and "half"? )。

2。 A peasant woman came to the market with some apples. The first customer bought half of the apples and added the other half. The second customer bought the remaining half and added another half. The third customer bought the remaining half, the second time added the other half, and so on.

When the sixth customer bought the remaining half of the fifth time and added another half, the peasant woman just sold out all the apples. So, how many apples did the peasant woman take to the market?

Answer and hint: The peasant woman took 63 apples to the market.

If the last customer (that is, the sixth customer) gets 1 whole apple, then the problem can be solved immediately, that is, the fifth customer gets 2 apples, the fourth customer gets 4 apples, the third customer gets 8 apples, and so on. The remaining number of apples is: 1+2+4+8+65438.