4: Proportional Relationships and Percentages Last updated Jan 25, 2020 Save as PDF 3.3.2: Stained-Glass Windows 4.1: Proportional Relationships with Fractions Page ID34997 Illustrative MathematicsOpenUp Resources ( \newcommand{\kernel}{\mathrm{null}\,}\) 4.1: Proportional Relationships with Fractions4.1.1: Lots of Flags4.1.2: Ratios and Rates With Fractions4.1.3: Revisiting Proportional Relationships4.1.4: Half as Much Again4.1.5: Say It with Decimals4.2: Percent Increase and Decrease4.2.1: Increasing and Decreasing4.2.2: One Hundred Percent4.2.3: Percent Increase and Decrease with Equations4.2.4: More and Less than 1 Percent4.3: Applying Percentages4.3.1: Tax and Tip4.3.2: Percentage Contexts4.3.3: Finding the Percentage4.3.4: Measurement Error4.3.5: Percent Error4.3.6: Error Intervals4.4: Let's Put it to Work4.4.1: Posing Percentage Problems