Significant figures will be used extensively throughout the year. Below are some videos.
Intro to significant figures - from Khan Academy
Rules of significant figures -
Adding and subtracting with significant figures - from Khan Academy
Multiply and divide with significant figures - Khan Academy
How to calculate percentage error using the formula
Rounding to significant figures
How to solve 3 variable system -from Khan Academy
Introduction to Logarithms - from Khan Academy
Notes on how to solve 3 variable system
Finding points of intersection - Desmos