Expressions, powers and clever calculation
Recognise the model, justify the rule and solve independently.
IKMC Grades 7-8 - Selected Topics
Evaluate expressions in the correct order of operations, treating a fraction bar as brackets around the whole numerator and the whole denominator.
Explain why $a^m\times a^n=a^{m+n}$ for powers of the same base, and why a sum such as $a^m+a^n$ cannot be simplified in this way.
Use $a^2-b^2=(a-b)(a+b)$ to avoid expanding large squares.
Sum an arithmetic sequence by pairing terms, counting the terms correctly and handling any unpaired middle term.