Mathorio
Answer key
Introduction to Exponents
Show your work for each problem.
- 1.What does mean?
- a)
- b)
- c)
- d)
Answer:
means 2 multiplied by itself 4 times: . The exponent (4) tells us how many 2s to multiply.
- 2.Calculate
Answer: 25
. The exponent 2 means we multiply 5 by itself once.
- 3.In the expression , what is the base?
- a)3
- b)7
- c)343
- d)21
Answer: 7
In , the base is 7 (the number being multiplied) and the exponent is 3 (how many times to multiply).
- 4.Calculate
Answer: 8
. First , then .
- 5.Calculate
Answer: 16
- What is the base in ? 4
- What is the exponent? 2
- What is ? 16
- 6.Calculate
Answer: 81
- 7.Which is greater: or ?
- a)
- b)
- c)Cannot determine
- d)They are equal
Answer:
and . Since , is greater. Don't assume the larger base always wins!
- 8.Write using an exponent, then calculate.
Answer: 7776
- What number is being repeated? 6
- How many times is 6 multiplied? 5
- Write in exponential form: 5
- Calculate 7776
- 9.What is ?
Answer: 10000
(1 followed by 4 zeros). This is ten thousand.
- 10.Calculate
Answer: 64
- What is ? 4
- What is ? 8
- What is ? 16
- What is ? 32
- What is ? 64
- 11.What is for any number n?
- a)0
- b)1
- c)n
- d)n + 1
Answer: n
Any number to the power of 1 equals itself. , , .
- 12.Calculate
Answer: 625
- 13.A cube has sides of 6 cm. What is its volume?
Answer: 216
- What formula do we use for volume of a cube? side cubed
- What is the side length? 6
- Write in exponential form: Volume = ? 6^3
- Calculate 216
- 14.Which is the correct way to read ?
- a)Four times five
- b)Five fours
- c)Four to the fifth power
- d)Five to the fourth power
Answer: Four to the fifth power
is read as 'four to the fifth power' - the base (4) is raised to the exponent (5).
- 15.A bacterium doubles every hour. Starting with 1, how many are there after 5 hours?
Answer: 32
- After 1 hour, how many bacteria? 2
- After 2 hours? 4
- After 3 hours? 8
- After 4 hours? 16
- After 5 hours? (This is ) 32
- 16.What is ? (This is 1 kilobyte in bytes)
Answer: 1024
. This is why 1 KB = 1024 bytes in computing!
- 17.A square has area 64 square cm. What is the side length?
Answer: 8
- Area of square = side squared. If Area = 64, then side = ? 8
- Verify: What is ? 64