Ontario · Grade 8
G8.B1.3
Grade 8 — Estimate and calculate square roots, in various contexts.
The 2 skills that cover it
- Square & Cube RootsUndo a square or a cube: find the root of a perfect square or cube, solve x^2 = p and x^3 = p, and estimate the roots that are not whole numbers.Read the lesson →
- Simplifying RadicalsWrite a square root in simplest form by pulling out perfect-square factors, then add, multiply and divide radicals, and clear a root from a denominator.Read the lesson →
What a student should be able to do
- Evaluate square roots of perfect squares and cube roots of perfect cubes.
- Solve equations of the form x2 = p and x3 = p, remembering both square roots.
- Estimate a non-perfect square root between two whole numbers and to one decimal place.
- Use roots to find the side of a square or the edge of a cube from its area or volume.
- Simplify a square root such as sqrt(50) to 5 sqrt(2) by factoring out the largest perfect square.
- Multiply and divide square roots, and simplify the product.
- Add and subtract like radicals after simplifying each one.
- Rationalise a denominator such as 6 / sqrt(3).