Thanks!

Can you advise what are the key concepts/rules required for this logarithm topic?

My kid can’t fully understand.

Key concepts
Logarithms are essentially a reverse engineering of expressing powers/exponentials. It is difficult to explain over text so I would recommend that your daughter watch the following videos which do a good job of breaking the key concepts down. That said, I assume she already has a good foundation in basic algebraic manipulation and indices rules learnt in E-Maths which are necessary to solve or simplify most logarithm questions for her level.

• Intro to logarithms
• Evaluating logarithms
• Relationship between logarithms and exponentials
• e and compound interest

Key logarithm rules

• log _a (b) = x, a^x = b (Intro to logarithms)
• log _a (xy) = log _a (x) + log _a (y) (Using the logarithm product rule)
• log _a (x/y) = log _a (x) – log _a (y)
• log _a (b^x)= x log _a (b) (Using the logarithm power rule)
• log _a (b) = log a / log b (Using the logarithm change of base rule)
• log _e (a) = In (a)

Thanks for the advice.