Units Digits of Powers of 33

Units Digits of Powers of 33

Assessment

Interactive Video

Mathematics

9th - 10th Grade

Hard

Created by

Thomas White

FREE Resource

The video tutorial addresses the problem of finding the units digit of 33 raised to the 408th power. It explains why direct calculation is impractical and explores a method of identifying patterns in the units digits of powers of 33. By recognizing a repeating cycle in the units digits, the tutorial demonstrates how to determine the units digit of large powers efficiently. The key insight is that the units digit of a product depends only on the units digits of the factors, allowing for a simplified approach to solving the problem.

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7 questions

Show all answers

1.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

Why can't we directly calculate 33 to the 408th power using a calculator?

The calculator cannot handle numbers that large.

The calculator will automatically round the result.

The calculator will give an incorrect result.

The calculator will display the result in binary.

2.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the first step in finding the units digit of 33 to the 408th power?

Calculate 33 to the 408th power directly.

Look for a pattern in the units digits of smaller powers of 33.

Use a scientific calculator to find the exact number.

Estimate the number using logarithms.

3.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the units digit of 33 squared?

3

1

9

7

4.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

How is the units digit of a product determined?

By the units digit of the larger number.

By the average of the units digits of the numbers being multiplied.

By the sum of the units digits of the numbers being multiplied.

By the units digits of the numbers being multiplied.

5.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the units digit of 33 to the third power?

3

9

7

1

6.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What pattern is observed in the units digits of powers of 33?

The units digit is always 3.

The units digit repeats every four powers.

The units digit is random.

The units digit increases by 1 with each power.

7.

MULTIPLE CHOICE QUESTION

30 sec • 1 pt

What is the units digit of 33 to the 408th power?

1

7

9

3