Chessboard Grains and Mathematical Proofs

Chessboard Grains and Mathematical Proofs

Assessment

Interactive Video

Mathematics

9th - 10th Grade

Hard

Created by

Thomas White

FREE Resource

The video narrates an Indian legend about the origins of chess, where an inventor requests grains of wheat on a chessboard, doubling on each square. The king, realizing the enormity of the request, orders the inventor's execution. The video explains the mathematical concept behind the request, showing how the sum of grains equals 2^64 - 1, using a simple trick of doubling and subtracting.

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8 questions

Show all answers

1.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What was the inventor's request to the king in the legend of chess?

Grains of wheat on a chessboard

A palace made of gold

A kingdom of his own

A lifetime supply of food

2.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

How many grains of wheat were placed on the second square of the chessboard?

Four

Eight

Two

One

3.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What mathematical concept is used to represent the doubling pattern of grains?

Powers of two

Addition

Subtraction

Multiplication

4.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the formula for the sum of grains on the chessboard?

2^63 + 1

2^64 + 1

2^63 - 1

2^64 - 1

5.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What did the king do when he realized the inventor's trick?

Made him a royal advisor

Rewarded him with more grains

Gave him a kingdom

Ordered him to be killed

6.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What simple mathematical trick is used to derive the formula for the sum of grains?

Adding and multiplying

Multiplying and adding

Doubling and subtracting

Dividing and subtracting

7.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What happens when you subtract the original amount from the doubled amount in the series?

The series becomes infinite

All terms cancel out except the first and last

The series becomes zero

You get a negative number

8.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the final result of the mathematical proof presented in the video?

2^63 - 1

2^64 + 1

2^63 + 1

2^64 - 1