Essay: I am a calculation expert with 600 words.

My mother gave me ten yuan years ago and asked me to buy two packs of instant noodles and a bottle of my favorite milk. When I came to the small shop in the community, I found out that bagged instant noodles cost 1 yuan and 20 cents, and bowls cost 3 yuan and 50 cents. After thinking about it, the bagged instant noodles were a good deal. So I bought two bags of instant noodles and a bottle of milk for 1 yuan and 80 cents. I gave the 10 yuan from my mother to the salesperson, and she gave me 6 yuan and 80 cents. I happily took it. Went home with our things. On the way home, I was thinking that two packs of convenience cost 1 yuan and 2 cents each. The total was 2 yuan and 4 cents. Adding the milk was 1 yuan and 80 cents, the total was 4 yuan and 2 cents. I gave her ten yuan and she should find it. I'm fine with 5 yuan and 80 cents, ah! She actually gave me an extra 1 yuan. So, I quickly ran to the canteen and returned the extra 1 yuan to my aunt. She said in surprise: "You are such a smart, honest and good boy."

On the way home, I was thinking about how important it is to learn mathematics well