2 RMB 1, 4 bottle caps 1, 2 empty bottles 1,1How many bottles of beer can I drink?

Analysis:

1, first use 10 yuan to buy all five bottles of beer, and after drinking, there are five caps and five empty bottles;

2. After 1 bottle of beer, take 4 bottle caps, and 2 bottles of beer take 4 empty bottles. After drinking it all, there are four bottle caps and four empty bottles left.

3. Replace 4 bottle caps with 1 bottle of beer and 4 empty bottles with 2 bottles of beer. After drinking, you will get three bottle caps and three empty bottles.

4. Replace 2 empty bottles with 1 bottle of beer, and get 4 bottle caps and 2 empty bottles after drinking;

5. 1 bottle of beer uses 4 caps, 1 bottle of beer uses 2 empty bottles, leaving 2 empty bottles and 2 caps after drinking;

6. Finally, we exchanged two empty bottles for 1 bottle of beer. After drinking, we got three bottle caps and 1 empty bottles.

At this point, it is impossible to exchange beer. One * * * is fifteen bottles of beer.

Extended data

Name of the added section:

4+5=9

Where: 4 is an addend,+is a plus sign, 5 is an addend, = is an equal sign, and 9 is a sum. Expression: Addendum+Addendum = sum.

Addition has several important properties.

1 is interchangeable, which means the order is not important.

They are interrelated, which means that when two or more numbers are added, the order of addition is not important.

3. Repeatedly adding 1 is the same as counting; Adding 0 will not change the result.

4. Addition also follows related operations (such as subtraction and multiplication).