Simple Estimation

At times, we may not know or need an exact count of things and an estimate is sufficient for the purpose at hand.

For example, your school headmaster might know the exact number of students enrolled in your school, but you may only know an estimated count.

How many students are in your school? About 150? 400? A thousand?

Paromita’s class section has 32 children. The other 2 sections of her class have 29 and 35 children.

So, she estimated the number of children in her class to be about 100.

Along with Class 6, her school also has Classes 7–10 and each class has 3 sections each.

She assumed a similar number in each class and estimated the number of students in her school to be around 5001000.

We shall do some simple estimates. It is a fun exercise, and you may find it amusing to know the various numbers around us. Remember, we are not interested in the exact numbers for the following questions.

Share your methods of estimation with the class.

1. Steps you would take to walk:

Instruction

2. Number of times you blink your eyes or number of breaths you take:

3. Name some objects around you that are:

Try to guess within 30 seconds. Check your guess with your friends.

1. Number of words in your maths textbook:

a. More than 5000

b. Less than 5000

Solution : ab

More than 5000, most textbooks contain well over 5000 words, considering explanations, exercises, and examples.

2. Number of students in your school who travel to school by bus:

a. More than 200 , b. Less than 200

Solution : ab

More than 200 , In most schools, it is common for a large number of students to travel by bus, especially if the school has many students from distant areas.

3. Roshan wants to buy milk and 3 types of fruit to make fruit custard for 5 people. He estimates the cost to be ₹100. Do you agree with him? Why or why not?

Solution : NoYes,

I do not agree.

The cost of 3 types of fruit along with milk for 5 people is likely to exceed ₹100, depending on the fruits chosen. Fruits like apples, bananas, or grapes, along with a litre of milk, may add up to more than ₹100.

4. Estimate the distance between Gandhinagar (in Gujarat) to Kohima (in Nagaland).

Hint: Look at the map of India to locate these cities.

Solution : The estimated distance between Gandhinagar and Kohima is around to km, based on their positions on the map of India

5. Sheetal is in Grade 6 and says she has spent around 13,000 hours in school till date. Do you agree with her? Why or why not?

Solution :,

I do not agree.

Let’s estimate: On average, a student spends about 6 hours per day in school.

In a school year, there are approximately 200 school days, so that's about 6 × 200 = hours per year.

If Sheetal had been in school for 6 years, she would have spent approximately 1,200 × 6 = hours in school. This is much less than 13,000 hours.

6. Earlier, people used to walk long distances as they had no other means of transport. Suppose you walk at your normal pace. Approximately, how long would it take you to go from:

a. Your current location to one of your favourite places nearby.

If it’s nearby, like a park or store within 1-2 km, it may take about 20–3060-2hrs minutes to walk.

b. Your current location to any neighbouring state’s capital city.

If a neighbouring state’s capital is around 100–30010-15 km away, it would take several days to weeks to walk, depending on the distance and terrain.

c. The southernmost point in India to the northernmost point in India.

The distance from Kanyakumari to Kashmir is approximately 3,500 km. At an average walking speed of 5 km/hour, walking continuously would take about 700 hours, which is around days of walking without breaks. However, factoring in rest and food, it could take about 2–3 months to complete.

7. Make some estimation questions and challenge your classmates!