On the day of National Day, my father and I had lunch and played 24 games. I won from beginning to end, and my father said, "What are your skills?" I said: "calculating 24 points skillfully" is a math game, which is easy to learn, can strengthen the brain and improve intelligence, and is an extremely beneficial activity. The content of the clever 24-point game is as follows: there are 52 cards left in a deck, and 4 cards can be randomly drawn (called secondary cards) (if you only use 40 cards of 1 ~ 10 for initial practice). Add, subtract, multiply and divide (brackets can be added) to calculate that the number on the card surface is 24. Each card can only be used once. If the cards drawn are 3, 8, 8 and 9, then the formula is (9-8) × 8× 3 or 3× 8+(9-8) or (9-8).

As a poker intelligence game, we should also pay attention to skills in calculation. When calculating, we can't try different combinations of the four numbers on the card, let alone tinker with them. Let me introduce several common methods that are easy to learn and master:

1. Solve with 3× 8 = 24 and 4× 6 = 24.

Try to add the four numbers on the card face to 3 and 8, 4 and 6, and then multiply them. For example, 3,3,6 and 10 can form (10-6 ÷ 3) × 3 = 24, etc. For example, 2, 3, 3, 7 can be in the form of (7+3-2 )×

2. Use the operational characteristics of 0, 1 1 to solve it.

For example, 3,4,4,8 can form 3× 8+4-4 = 24,4,5, J and K can form11× (5-4)+13 = 24 and so on.

3. In the deck with solutions, the following six solutions are widely used: (We use A, B, C and D to represent the four numbers on the deck)

①(a—b)×(c+d)

Such as (10-4) × (2+2) = 24, etc.

②(a+b)÷c×d

Such as (10+2) ÷ 2× 4 = 24, etc.

③(a-b÷c)×d

Such as (3-2 ÷ 2) × 12 = 24, etc.

④(a+b-c)×d

Such as (9+5-2) × 2 = 24, etc.

⑤a×b+c—d

Such as11× 3+l-10 = 24, etc.

⑥(a-b)×c+d

Such as (4-L) × 6+6 = 24.

When students are playing games, they might as well try the above methods. It should be noted that according to the accurate calculation of the computer, four cards (52 cards) in a deck can be randomly selected with 1820 different combinations, of which 458 cards can't calculate 24 points, such as A, A, A and 5.

It is not difficult to see that "calculating 24 points skillfully" can greatly mobilize the coordinated activities of eyes, brain, hands, mouth and ears, which is very helpful to cultivate our rapid mental arithmetic ability and reaction ability. "

Dad said, "Great! I will send you a model plane. "

It seems that life is really inseparable from mathematics!