# 7.18: Save More

**Save More - Reason Proportionally with Percents**

**Teacher Notes**

Students are presented with prices of sets of items at two different stores, and a coupon that can be applied to the purchase at both stores. To determine the better buy, students first reason proportionally to figure out the costs of the items at each store. Then, they apply the coupon in order to determine the discounted cost, and compare those costs to figure out the savings.

To determine the total cost after applying the coupon, students may use either a one- or two-step process. On the teaching page, we use the one-step process in the Solve step and the two-step process in the Check step. For example, if an item is discounted 10%, then its new price is 90% of the original price. So, multiplying the original price by 0.9 will give the discounted price using one computational step. For the two-step method, the discount is taken first (10% of the original price is the discount). For the second step, the amount of the discount is subtracted from the original price to get the discounted price.

**Solutions**

Buy 2 tubes of toothpaste. Use the coupon. Which store has the better buy? How much less is the cost at that store?

Buy 1 comb. Use the coupon. Which store has the better buy? How much less is the cost at that store?

Buy 4 boxes of band aids. Use the coupon. Which store has the better buy? How much less is the cost at that store?

Buy 2 boxes of tissue. Use the coupon. Which store has the better buy? How much less is the cost at that store