The mathematics textbook is 20 years long

The mathematics textbook is 20 years long


Cm (CM)



A math book is about 2 ()


A mathematics book is about 2 (decimeters) long



Use a 100 mm long rope to measure the length of the math textbook. After measuring twice, there is still 10 mm left. How long is the math textbook?


100×2-10=190mm