Understanding a Surprising Calculation

Understanding a Surprising Calculation

Assessment

Interactive Video

Mathematics

5th - 8th Grade

Hard

Created by

Jackson Turner

FREE Resource

This video tutorial introduces a surprising calculation that always results in 8, regardless of the initial number chosen. The video walks through a series of mathematical steps, including subtraction, multiplication, addition, and division, to demonstrate this consistent outcome. It further explains the process using algebraic expressions and simplifies them to prove the result. The tutorial concludes by generalizing the calculation to work with any real number, not just counting numbers.

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9 questions

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1.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the first step in the surprising calculation process?

Multiply the number by 3

Add 12 to the number

Think of any counting number

Subtract 1 from the number

2.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

In the calculation process, what do you do after subtracting 1 from your number?

Divide the result by 3

Multiply the result by 3

Add 5 to the result

Add 12 to the result

3.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What variable is used to represent the unknown counting number in the explanation?

y

z

x

a

4.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

After simplifying the expression 3x - 3 + 12, what is the result?

3x - 9

3x + 12

3x + 9

3x + 3

5.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the result of dividing the expression 3x + 9 by 3?

x + 8

x + 5

x + 3

x + 9

6.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the final result after subtracting the original number from x + 8?

5

8

x

0

7.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the significance of the number 8 in this calculation?

It is the number you subtract

It is the result of the calculation

It is the number you start with

It is the number you add

8.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the final step in the calculation process?

Add 5 to the result

Subtract the original number

Multiply by 3

Divide by 3

9.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

Can this calculation be applied to any real number?

No, only to counting numbers

Yes, to any real number

No, only to integers

Yes, but only to positive numbers