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Square Roots and Cube Roots Worksheet with Answers – Grade 8 (Free PDF)

Last updated: October 22, 2026 · Written by the Math Made Easy math teachers

Grade 8 Math Worksheets – Mathbot, the Math Made Easy robot coach, with free printable worksheets for Grade 8

Looking for a square roots and cube roots worksheet for grade 8? Then this Grade 8 worksheet on Solving With Square and Cube Roots gives problems ranked from easy to hard. These 20 problems address Standard 8.EE.A.2: solving x² = p and x³ = p, using square and cube root symbols, recognizing perfect squares and cubes, and knowing that √2 is irrational.

Begin with the easy roots and move toward estimates and real measurements. Give exact answers first, then approximations when a question asks for them.

Standards: 8.EE.A.2 · Level: Grade 8

Problem 2 Evaluate cube roots ★★★

Evaluate: (a) ∛27 (b) ∛125 (c) ∛(−8) (d) ∛18

Problem 3 Spot the perfect squares ★★★

Which of these numbers are perfect squares: 48, 81, 100, 150, 196?

Problem 4 Spot the perfect cubes ★★★

Which of these numbers are perfect cubes: 9, 64, 100, 216, 1,000?

Problem 5 Two small equations ★★★

Solve: (a) x² = 49 (b) x³ = 125

Problem 6 Patio side length ★★★

A square patio has an area of 169 square feet. How long is each side?

169 ft²side = ?
Square patio.

Problem 7 Fractions and decimals ★★★

Solve: (a) x² = 81100 (b) x² = 0.16

Problem 8 Negative and fractional cubes ★★★

Solve: (a) x³ = −64 (b) x³ = 27343

Problem 9 A root that is not whole ★★★

Solve x² = 50. Give the exact solutions and approximate each to the nearest hundredth.

Problem 10 A cube root estimate ★★★

Solve x³ = 30 and estimate the answer to the nearest tenth.

Problem 11 Cube-shaped box ★★★

A cube-shaped gift box holds 216 cubic inches. Find its edge length.

edge = ?V = 216 in³
Gift box.

Problem 12 Two-step equations ★★★

Solve: (a) 2x² = 98 (b) x³ + 5 = 69

Problem 13 Estimate two roots ★★★

Estimate to the nearest tenth: (a) √200 (b) ∛100

Problem 14 Solutions on a number line ★★★

The two orange points show the solutions of x² = 20. Write the solutions exactly and estimate each to the nearest tenth.

−6−4−20246
Solutions of x² = 20.

Problem 15 Mural frame ★★★

A square mural has an area of 289 square feet. A frame around its edge costs $3.25 per foot. Find the side length, the perimeter and the cost of the frame.

Problem 16 Storage cube surface ★★★

A cube-shaped bin has a volume of 343 cubic centimeters. Find the edge length and the total surface area.

V = 343 cm³
Storage bin.

Problem 17 Garden fence ★★★

A square garden has an area of 90 square feet. Estimate the amount of fencing needed to enclose it, to the nearest tenth of a foot.

Problem 18 Why is √2 irrational? ★★★

Show that √2 lies between 1.41 and 1.42, then explain what it means that √2 is irrational.

Problem 19 Two cubes ★★★

Cube A has an edge of 6 inches. Cube B has a volume of 300 cubic inches. Which cube has the longer edge, and by about how much to the nearest tenth?

Problem 20 Check a claim ★★★

Dan says both x² = −16 and x³ = −64 have the solution −4. Decide whether each claim is right and explain.

View the Square Roots And Cube Roots worksheet answer key