Alain Dupont, a famous French dog trainer, invented a simple method to teach dogs to do arithmetic:

Most importantly, you must be able to make your dog bark in a certain posture. This gesture seems unimportant, but it is actually an order.

Next time you feed the dog, you can raise your hand and let it bark. Once the dog barks, you reward it, then put down your hand and point at it with your palm. This is an order to stop barking.

Soon, you can easily raise your hand to let it bark, and put it down and it won't bark.

In this way, the next time you are with friends, you can easily work out several math problems.

After asking questions, you quietly raise your hand to let the dog bark. When it barks the same number of times as the answer, you put your hand down and make it stop. Now, you can reward it.

Remember, the key is to count the number of times you bark at the dog!