4: Proportional Relationships and Percentages Last updated Save as PDF Page ID 34997 Illustrative Mathematics OpenUp Resources 4.1: Proportional Relationships with Fractions 4.1.1: Lots of Flags 4.1.2: Ratios and Rates With Fractions 4.1.3: Revisiting Proportional Relationships 4.1.4: Half as Much Again 4.1.5: Say It with Decimals 4.2: Percent Increase and Decrease 4.2.1: Increasing and Decreasing 4.2.2: One Hundred Percent 4.2.3: Percent Increase and Decrease with Equations 4.2.4: More and Less than 1 Percent 4.3: Applying Percentages 4.3.1: Tax and Tip 4.3.2: Percentage Contexts 4.3.3: Finding the Percentage 4.3.4: Measurement Error 4.3.5: Percent Error 4.3.6: Error Intervals 4.4: Let's Put it to Work 4.4.1: Posing Percentage Problems