Total length of road = 12 km 600 m
= 12,600 m
Total number of days to complete the work
= 6 days
So, the workers lay 12,600 m ÷ 6 = 2,100 m or 2 km 100 m of road each day.
NCERT Textbook Page 68
Let Us Estimate
Estimate the following. Share your reasoning in class.
1. The height of the tallest building in your neighbourhood. What did you use as a reference to estimate the height?
2. The height of the tallest tree in your neighbourhood. What did you use as a reference?
3. The depth of a well or swimming pool in your neighbourhood. How did you find out?
Solution:
Do it yourself.
Let Us Explore
In daily life, we use other units of measuring length as well. Height is usually measured in feet and inches. Look at your ruler to see if inches are also marked on it. Find out how many cm and mm equal 1 inch.
1 inch = 2 cm 5 mm
1 foot = 12 inches or 30 cm.
Solution:
Do it yourself.
NCERT Textbook Page 69
Measure Your Height
Stand against a wall and mark your height. Measure the distance between the floor and the marked point in feet and inches. Similarly, other students in the class can also measure their heights.
Find out who is the tallest student in your class. What is his or her height in feet and inches?
Solution:
Do it yourself.