Evaluating Expressions (Leaving Cert Mathematics): Flashcards

Finding its value by substituting numbers for variables

$3 × x$

$x × x$

$2 × a × a$ (square first, then multiply by 2)

Always square before you multiply

$4$ (positive, not negative)

$(-2)^2 = 4$, but $-2^2 = -4$

BODMAS or PEMDAS

Always use brackets to avoid sign errors

$18$ (not $36$). Do $2(9) = 18$

$6$

Work step by step, show your working clearly