The formula of mathematics enrollment rate in primary school 1-4 grade.
Unit of length measurement and propulsion rate: 1 parsec (pc)=3.26 16 light years 1 light years = 299,792,458 meters (m) 1 km =1km =65438. 1 decimeter =10cm1cm =10mm (mm) 1 mm =10mm (dmm) 1 micron =/klc. 65438= 100 ha1km2 =100000 m2 (m2)1ha =10000 m2/m2 =1m2. Volume measurement unit and rate: 1 m3 = 1000 cubic decimeter (dm3) 1 cubic decimeter = 1 000 cubic centimeter (cm3) 1 cubic decimeter =1liter (m3). (4) Mass unit and speed: 1 ton (T)= 1000 kg1kg = 1 kg = 1000 g (g) (5) Time unit and speed: 65438. 1 year = 1 February (month) 1 month =30 days (note: February in a normal year is 28 days, and February in a leap year is 29 days,1,3,5,7,8, 10.