Exponents and Roots unit pack (Grades 6-8 · CCSS 6.EE.A.1, 8.EE.A.1, 8.EE.A.2, 8.NS.A.2): every worksheet and exit ticket for this unit, ready to print in one go. The answer keys print at the end, each on its own page, so you can leave them off. To make a PDF, click Print and choose "Save as PDF." Games: Exponent Racer · Exponent Hoops · Rooted to the Spot
Exponent Rules
Grades 6–8 · CCSS 6.EE.A.1, 8.EE.A.1 · Pairs with the Exponent Racer game
In 53, 5 is the base and 3 is the exponent: 53 = 5 × 5 × 5.
Same base: multiply → add the exponents, divide → subtract them. Power of a power → multiply them.
a0 = 1, and a−n = 1 / an.
Key vocabulary
- base: the number being multiplied; in 4³, the base is 4
- exponent: how many times the base is used as a factor; in 4³, the exponent is 3
- power: a base with an exponent, like 4³
- product of powers: same base, multiply: add the exponents (2³ · 2⁴ = 2⁷)
- quotient of powers: same base, divide: subtract the exponents (5⁶ ÷ 5² = 5⁴)
- power of a power: multiply the exponents ((3²)&sup4; = 3⁸)
- zero exponent: any nonzero base to the zero power is 1 (7⁰ = 1)
- negative exponent: means one over the positive power: 5⁻² = 1/5² = 1/25
Part A: Evaluate each power
Part B: Write as a single power
Part C: Zero and negative exponents (write as a fraction or whole number)
Part D: Vocabulary and reasoning
17. In
64, name the base and the exponent, and find the value of the power.
base exponent value
18. Find the mistake. Sam wrote
43 = 12. What did Sam do wrong? What is the correct value?
Correct:
19. The distance from Earth to the Moon is about 4 × 10
5 km. Write 10
5 as a whole number, then write the distance as a whole number.
105 = distance ≈ km
Exit Ticket: Exponent Rules
Grades 6–8 · CCSS 8.EE.A.1
1. Simplify, then evaluate. Name each rule you used.
(23)2 × 2−4=
2. Is
10−3 greater than 0? Less than 1? Write it as a decimal.
=
3. Explain why
65 ÷ 65 = 60, and what 6
0 equals.
60 =
Exponent Rules with Variables
Grade 8, Algebra 1 · CCSS 8.EE.A.1 · Pairs with the Exponent Hoops game
The rules work for letters just like numbers. Same base: xa · xb = xa+b,
xa ÷ xb = xa−b, (xa)b = xab,
x0 = 1, x−n = 1 / xn. Write answers with positive exponents.
Key vocabulary
- base: the number or variable being multiplied; in x&sup5;, the base is x
- exponent: how many times the base is used as a factor; in x&sup5;, the exponent is 5
- power: an expression with a base and an exponent, like x&sup5;
- product of powers: same base, multiply: add the exponents (x² · x⁴ = x⁶)
- quotient of powers: same base, divide: subtract the exponents (x⁷ ÷ x³ = x⁴)
- power of a power: multiply the exponents ((x²)³ = x⁶)
- zero exponent: any nonzero base to the zero power is 1 (x⁰ = 1)
Part A: Multiplying powers (2-pointers)
Part B: Dividing powers
Part C: Power of a power (3-pointers)
Part D: Put the rules together
16. Find the mistake. Taylor wrote
x3 · x5 = x15. What rule did Taylor use by mistake? What's the correct answer?
Correct:
Exit Ticket: Exponent Rules with Variables
Grade 8 · CCSS 8.EE.A.1
1. Simplify.
a3 · a5 ÷ a2=
2. Simplify. Use a positive exponent.
(y2)−3=
3. Why can't
x2 · y3 be written as a single power?
Penalty Kick Roots
Grade 8 · CCSS 8.EE.A.2, 8.NS.A.2 · Pairs with the Rooted to the Spot game
A square with an area of 49 has sides of 7, because 7 × 7 = 49. So √49 = 7. ·
∛8 = 2 because 2 × 2 × 2 = 8.
Key vocabulary
- perfect square: a whole number squared, like 49, 64 or 81
- square root (√): the number that, times itself, gives the original number: √81 = 9
- perfect cube: a whole number cubed, like 8, 27 or 64
- cube root (∛): the number that, used three times as a factor, gives the original number: ∛64 = 4
Part A: Squares and square roots
Part B: Side of a square
5. A square rug has an area of 81 square feet. How long is each side?
feet
6. A square field has an area of 225 square meters. How long is each side?
meters
Part C: Estimate and cube roots
7. √30 is between which two whole numbers?
and
8. √90 is between which two whole numbers?
and
11. Closer to which? √20 is between 4 and 5. Is it closer to 4 or to 5? Explain how you know.
12. Find the mistake. Jordan said √36 = 18 because 36 ÷ 2 = 18. What went wrong? What is √36 really?
Correct: √36 =
Exit Ticket: Square Roots and Cube Roots
Grade 8 · CCSS 8.EE.A.2, 8.NS.A.2
1. A square has an area of 121 square units. How long is each side?
2. √60 is between which two whole numbers?
and
Answer Key: Exponent Rules
For the teacher
2·2·2·2·2 = 32
3·3·3·3 = 81
- 1,000
- 1 (any nonzero base to the zero power)
- 5
4·4·4 = 64
- Add exponents: 36
- Subtract exponents: 54
- Multiply exponents: 26 (= 64)
- 106
- 78
2^(3+5−4) = 24 (= 16)
1 / 5² = 1/25
1 / 2³ = 1/8
3^(2−5) = 3⁻³ = 1 / 3³ = 1/27
9⁰ = 1
- Base 6, exponent 4, value
6·6·6·6 = 1,296
- Sam multiplied the base by the exponent (4 × 3). Correct:
4·4·4 = 64
- 105 = 100,000; the distance is about 400,000 km
Common mistakes to watch for: multiplying base × exponent (#18), multiplying exponents in the product rule (38 for #7), and reading a negative exponent as a negative number (−25 for #13). Exponent Racer's wrong answer choices are built from these same mistakes.
Answer Key: Exit Ticket
Exponent Rules
- Power of a power:
(2³)² = 2⁶. Product rule: 2⁶ × 2⁻⁴ = 2² → 4
10⁻³ = 1 / 10³ = 1/1000 = 0.001. Yes, it's greater than 0; yes, it's less than 1.
- Dividing with the same base subtracts exponents:
5 − 5 = 0. Any number divided by itself is 1, so 6⁰ = 1.
Quick read: an answer of 2 on #1 means the student added the exponents in (2³)² and got 2⁵ instead of 2⁶; a negative answer on #2 means they read the exponent as a negative number. Assign the matching skill in Exponent Racer.
Answer Key: Exponent Rules with Variables
For the teacher
- Add exponents: x8
- y9
a¹ · a⁴ → a5
b⁶ · 1 → b6
- Subtract exponents: x5
- y5
a⁰ → 1
b⁻³ → 1/b3
- Multiply exponents: x6
- y8
a⁻⁶ → 1/a6
b⁰ → 1
x^(4+2−7) = x⁻¹ → 1/x
y⁶ · y⁻⁴ → y2
- Group like bases:
x²·x⁵ · y³·y¹ → x7y4
- Taylor multiplied the exponents (the power-of-a-power rule). When multiplying powers, add them: x8
A quick proof for #16: write x³ · x⁵ as (x·x·x)(x·x·x·x·x) and count eight x's. In Exponent Hoops, each shot shows the rule used ("Add exponents"), so students hear the rule every time.
Answer Key: Exit Ticket
Exponent Rules with Variables
a^(3+5−2) → a6
y^(2·−3) = y⁻⁶ → 1/y6
- The rules only combine powers with the same base. x and y are different bases, so the exponents can't be added.
Quick read: a13 or a15 on #1 means the student multiplied the exponents; y−1 or y5 on #2 means they added in a power of a power.
Answer Key: Penalty Kick Roots
For the teacher
6 × 6 = 36
12 × 12 = 144
- 8 (8 × 8 = 64)
- 13 (13 × 13 = 169)
- 9 feet (9 × 9 = 81)
- 15 meters (15 × 15 = 225)
- 5 and 6 (25 < 30 < 36)
- 9 and 10 (81 < 90 < 100)
- 3 (3 × 3 × 3 = 27)
- 10 (10 × 10 × 10 = 1000)
- Between 4 and 5 (16 < 20 < 25). Closer to 4: 20 is 4 away from 16 but 5 away from 25. (√20 ≈ 4.47)
- Jordan divided by 2 instead of finding the number that times itself makes 36.
6 × 6 = 36, so √36 = 6
#12 is the most common mistake: halving instead of undoing the square. In the game, a wrong answer draws the square as a grid so students can see that 6 rows of 6 make 36.
Answer Key: Exit Ticket
Square Roots and Cube Roots
- 11 (11 × 11 = 121)
- 7 and 8 (49 < 60 < 64)
- 4 (4 × 4 × 4 = 64)
Quick read: 60.5 on #1 means the student halved the area; 21 on #3 means they divided by 3. Have them play with just Square Roots and Side of a Square turned on, where each wrong answer draws the square, then add Cube Roots.