In this unit you will stretch your number sense in three directions: very big and very small, the whole number line, and flexible forms.
First you will write very large numbers (like the distance to the Sun) and very small numbers (like the width of a red blood cell) in scientific notation, such as 1.5 × 10⁸ and 7.5 × 10⁻⁶. You will compare them and see how they are used every day, from phone storage to metric prefixes.
Next you will explore the real number system: natural numbers, whole numbers, integers, rational numbers and the new irrational numbers, like √2 and π, whose decimals never end and never repeat. You will compare and order all kinds of real numbers on a number line.
Then you will estimate square roots that are not whole numbers, like √50 ≈ 7.07, and use square roots of decimals and fractions to solve real problems with squares and circles.
Finally, you will use fractions, decimals and percents interchangeably, including percents over 100% and under 1%, to solve problems with sales tax, discounts, snowfall, savings and recipes.
Remember from Grade 7: you worked with numbers to one billion and powers of ten, perfect squares and their square roots, rational numbers, and conversions between fractions, decimals and percents. Grade 8 builds on all of it, and gets you ready for high school math. Every lesson has hands-on activities you can do at home, lots of practice and a short quiz. Strand A skills (social-emotional learning and mathematical processes) are woven in: explaining your thinking, choosing strategies, checking and persevering.
Curriculum expectations covered: B1.1, B1.2, B1.3, B1.4, with A1 woven in (Ontario Mathematics, Grade 8, 2020). Operations (B2), including recalling square numbers, multiplying and dividing by powers of ten mentally, and operations with integers, fractions and proportions, are in the Operations unit.