Selected essays of math diary 100 and math diary 100.

Today, my father and I went to the supermarket. Dad took me to the street corner where vegetables were sold. We bought 2 Jin of cucumber, 1 Jin of tomato and 2 Jin of my favorite potato. On the way back, my father asked me, "There are just four cucumbers. There are three of us, but my mother went to Jinan. How many do we each eat? " Recalling the division I learned before, I said, "4÷2=2, everyone eats two." Dad asked again, "These four cucumbers cost 2 3 yuan cents each. How much is each cucumber? " I thought about it and said, "3 yuan's 2 angles are 32 angles, and 32÷4=8, each of which is 8 angles." Dad nodded, smiled and said, "You're right!" Today, I am so happy! I bought my favorite vegetables and learned math knowledge. It's killing two birds with one stone!

Today is my second visit to the dentist, because I have decayed teeth. The doctor said that I should check it once or four times a week. I asked my mother when my teeth would be ready. Mom said, "It will be fine in a month. Do the math. How many days will it take to start from scratch? " I thought about it: a week is 7 days. I have seen it twice. I used 14 days, and there are still 4 times left, that is, 7×2+4×7=42 (days). It will take me 42 days to get better!

I must pay attention to oral hygiene in the future and never let my teeth get sick again!

Today, I learned millimeters, decimeters and kilometers. I know that smaller items are measured in millimeters, such as 3 mm thick books and 8 mm thick rubber. Glue stick 1 meter high, 2 meters high in coca-cola bottle. The school is kilometers from my home, and the speed is kilometers per hour.

1 m = 10 decimeter, 1 decimeter = 10 cm, 1 0 mm, 1 m = 100 cm.