Observations: The shaded area is one half of the whole area of the squared paper taken. To see this, cut the shaded portion and place it on the remaining part of the grid. It is observed that it completely covers the grid. Area of the whole squared paper is 10 × 11 cm^{2}

Area of the shaded portion is (10 × 11) / 2 cm^{2}

This verifies that, for n = 10, Σ n = n × (n + 1) / 2 The same verification can be done for any other value of n.

Answer the following after doing this activity:

- What is the sum of first 50 natural numbers?
- What is the sum of natural numbers between 60 and 80?
- What is the sum of first 100 multiples of 4?
- What is the sum of first 60 multiples of 9?

## 10 comments:

Thanks a lot for this it reeli helped!

Sid

thanks for help.

The blogger seemed to us to be super well, usefully and didactically because he presents images which facilitates the comprehension of the exposed problems, beside presenting videoes for those topics that are mas difficult to understand. The blogger presents many topics that we include in the studies of our career which undoubtedly is a help for the students and future teachers.

The blogger is of very easy access, the topics are presented in a list which makes us that the search realizes of way mas simple in addition he presents a bar of search where the person who accedes deposits the topic that searches doing mas simply to find it.

thanx a lottt,it was a great help:)

thnx

Thanxx rashmi mam u r grt.

:* sumit royal bengali

thnx sooooooooo much mam!

thanks a lot for this info...!

THANKU FOR THIS ANSWER. TO ALLLLL.

thank you for helping me

very helpfull

Post a Comment