Ayumi, a chef, wants to determine how many meals she cooked in
one evening. The table shows the four meals
she made and the number of people that
were served each meal. (Lesson 1-3)
Meal Number of People
Lasagna
27
Spaghetti & Meatballs 21
Steak & Potatoes
19
Shrimp Scampi
13
She uses the following steps to determine
how many total meals she cooked.
Step 1: 27 + 21 + 19 + 13
Step 2:27 +13 + 21 + 19
Step 3: (27 +13) + (21 +19)
Step 4: 40 + 40
Step 5: 80
Which property did Ayumi use in Step 3?