Mathematics education uncovered and recovered

Key Stage 3

The root mystery

What is $$\sqrt{25}$$? You probably know but let’s see what textbooks say. One Year 7 textbook explains: Key point: The inverse of square is square root. $$3^{2}=9 \enspace$$ so the square root of  $$9=\sqrt{9}=3$$   However, just next to this explanation there is a copy-and-complete exercise that reminds students that both $$4^{2}$$ and $$(-4)^{2}$$ […]

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