I had a good time with my sister, and my grandmother insisted on calling me and asking me to settle accounts with her.

Grandma bought 3 Jin 4 Liang eggs, 3 yuan and 50 cents per Jin. Grandma handed it in 12 yuan. How much should I get back? As soon as grandma's voice fell, grandpa said, "Change 1 minute!" "I don't believe that Grandpa can calculate so fast, so I use the mathematical knowledge I have learned to calculate: unit price multiplied by quantity = total price; Spent money = recovered money, exactly the same as grandpa's, and the change is 1 minute. I asked grandpa why he calculated so fast. It turned out that grandpa divided 3 yuan into 5 cents.

3 yuan +5 angle, first calculate 3.4 times 3= 10.2 yuan, then calculate 3.4 times 0.5, which is 3.4.

Half of it is 17 yuan, so a * * spent 1 1.9 yuan and paid 12 yuan, of course, a dime.

Yes After grandpa finished, I realized that he used multiplication and division.

Through this incident, I understand that mathematics can be used anywhere around us. Let mathematics serve us!

Solve the problem by yourself

There is a question on the test paper handed out today: Fold a rectangular piece of paper into an angle, as shown in the figure. The known angle is 1=70 degrees, and the angle is 2.

I thought about it for a long time, but I didn't come up with it. On second thought, the angle 1=70 degrees is equivalent to two 70 degrees, that is, 70×2= 140 degrees. Then use the inner angle of the triangle and 180 degrees-140 degrees =40 degrees.

It's as simple as that, as long as you think well and use your head more, you can do it.

The correct formula is: 180-70×2.

= 180- 140

=40 (degrees), 8, can you be more specific? Are you a pupil? Junior high school, high school?

How do I write, typo, or theoretical analysis?

QQ75309792 1。 You can find me on my QQ. Today, I have an appointment with my classmates to have a picnic outside. I went to the supermarket and bought a bottle of 5 yuan. A loaf of bread 2 yuan, buy three; A pack of beef jerky 3 yuan 6 jiao; A hillbilly chicken leg, 2 yuan.

Aunt smiled and said to me, *** 15 yuan, I gave it to my aunt 15 yuan. When I walked out of the supermarket, I calculated: No, 5+2×3+3.6+2= 16.6 yuan, my aunt took 1.6 yuan, and I gave it back to her. Aunt said, "You are an honest boy"!

Mathematics can also make me understand the truth of being a man. I'm so happy. I went out to buy breakfast for my mother this morning. It's sunny outside and the air is fresh. There are so many delicious foods in the small food market, including steamed buns, bean paste buns, fried dough sticks, pies and so on, as well as my favorite egg pancakes. It makes my mouth water. Unfortunately, my mother only gave me a little money to buy soybean milk. Well, I have to buy it and go home quickly. My aunt who sells soy milk greeted me for a long time, because I go to her every morning to buy soy milk. My aunt knows me very well and always gives me more. This time, while praising my ability, she was busy weighing soybean milk and greeting the guests next to her, and she was so busy that she was sweating. On the way, I thought, life is really not ... 3, is there a problem, 0,