400-word composition in the second grade of primary school: one step, two steps back.

Composition title: Take one step, take two steps back.

Keywords: two steps, one step, second grade of primary school

This article is applicable to: the second grade of primary school.

Composition source:

This 400-word composition is about the second grade of primary school. The title is: "Take one step, take two steps back". Everyone is welcome to contribute enthusiastically.

One step, two steps back.

-Mathematical exploration

"How many steps does it take to get to10m between two poles that are10m apart?" I can't stop thinking about this question. Dad knocked on the book and came over: "Beijing time is 20 o'clock sharp."

I patted my head and thought hard about this problem as if I didn't hear it. Dad saw that I didn't mean to sleep at all, and even didn't have time to yawn, so he came over and asked, "Baby, what fascinates you so much?" I read this question to my father. I saw my father sitting cross-legged on the bed like a rest, thinking for less than three seconds and giving an inaccurate answer: "It takes 30 steps." I don't understand: "How can it be 30 steps?" Dad even forgot to put on his shoes, so he dragged me to the floor and counted 10 bricks. He demonstrated, "If each brick is 1 m long, if I take one step forward and two steps back, it is equivalent to taking three steps to walk 1 m, so it is 10×.

I nodded thoughtfully, then shook my head, thinking: If you need 30 steps, it should be 1 1 m, because when you take the ninth step, you only need to take two steps back at 10 m, so you don't need to go back any more. Similarly, if you have a 10 step, when you walk again and then step back,

I strode forward and confidently said to my father, "Dad, your formula is wrong. It should be 10×3-3=27 steps. " "Why?" It was my father's turn to ask me this time. My naive father shook his head, waiting to see my joke. I naturally said the answer forcefully.

Dad gave me a thumbs-up and "self-criticized": I can't be careless in what I do in the future, otherwise the rocket won't get into the sky, haha! o(∩_∩)o…

Self-evaluation: This question has been bothering me for a long time and there is no answer. Last night, before I found a solution, I won Grandpa Li Yupei's "Boisne Devil" again, but my father and I had another argument, which ended in my victory. So I wrote it down, please give me some advice, thank you!