Yesterday, Teacher Ni told us about the unit of length, and we learned another knowledge. Teacher Ni took a pen and measured the platform. It was about nine red pens long. Teacher Ni also took a long ruler to measure the blackboard, about 4 feet long. Teacher Ni said, "Is the podium longer than the blackboard?" We said, "No."

Teacher Ni asked again, "Why not?" We replied, "The pen is shorter than the ruler." Teacher Ni smiled and said, "You are so smart. Their standards of measurement are different and the result is unfair.

We must study measurement in the first unit of school. By previewing the first unit, I know the units of measurement such as kilometers, millimeters, decimeters and tons, 1 000m = 1 km,1ton =1000kg. Dad asked me, "So, how many centimeters is 1 km?" ? I said, "1 km is equal to 1000 m. Just multiply 1000 m by100, which is equivalent to 100000 cm.

Dad said, "Not bad!" At this moment, my mother told me, "As long as we master the calculation rules of 1 km = 1000 m, 1 m = 1 cm, 1 cm = 10 mm, no matter how big,

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 should use dry rice as the unit to get to my home, and the speed should be kilometers per hour.

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

I found all kinds of rulers when I was sorting out cigarettes today. There is a 2-meter-long tape measure, which is 150 cm long, and several rulers of different lengths, some are 30 cm long, some are 20 cm long, some are 18 cm long, and some are 15 cm long. I converted them into newly learned decimeters and millimeters. 2 m =20 decimeter =200 cm =20000 mm, 10 cm = 15 decimeter.