Proportional reasoning involves thinking about relationships and making comparisons of quantities. For example, if a lemonade recipe requires 6 L of lemon concentrate and 14 L of water, this makes 20 L of lemonade. Proportional reasoning is used to determine that  3 L of lemon concentrate and 7 L of water are required to make half the amount of lemonade.

In this activity, you will use proportional reasoning to solve problems that involve equivalent ratios.

Important Mathematical Ideas

• A ratio compares two quantities of the same unit.
• Reasoning proportionally using multiplication and division produces equivalent ratios.
• Equivalent ratios are useful to make comparisons.