# Event Planning: Determining Cost & Materials

Instructor: Deborah Schell

Deborah teaches college Accounting and has a master's degree in Educational Technology.

When you're planning an event, you must be able to determine the quantity of items needed and the cost. In this lesson, you will learn about the methods to use to estimate materials and cost of an event.

## Determining the Quantity of Items Needed

Melissa is having a party to celebrate her birthday. She invited ten of her closest friends. Now she needs to figure out how much food she needs and how much it is going to cost. The problem is she doesn't know where to begin. Let's see if we can help Melissa with this problem.

In order to estimate how much the party will cost, Melissa needs to determine the quantity, or the amount, of food and drink she will need. First, Melissa must determine how much she thinks each guest at her party will eat and drink. Once she has determined that, then she can multiply the quantity per person by the number of guests.

Let's start with the quantity of food and drinks for Melissa's guests. Melissa would like to serve pizza at the party. She estimates that each guest will eat three slices of pizza. There are 11 people attending her party (10 guests plus Melissa). Therefore, Melissa will need 3 slices of pizza for each of the 11 guests. We can solve this problem by creating a formula:

Number of slices per person x Number of guests = Number of slices of pizza

3 x 11 = Number of slices of pizza

3 x 11 = 33

Melissa will need 33 slices of pizza. A typical pizza contains 8 slices of pizza, so Melissa must use division to determine how many pizzas she will need. The calculation is:

Total number of slices / Number of slices per pizza = Number of pizzas needed

33 / 8 = Number of pizzas needed

33 / 8 = 4.13

Melissa needs 4.13 pizzas to serve her guests. Since we can't order part of a pizza, we need to round up, which means Melissa needs 5 pizzas for her guests.

Now that Melissa has determined the amount of pizza needed, she must ensure that she will have enough lemonade for her guests to drink. She needs to determine how much lemonade to buy.

Let's assume that each guest will drink three cups of lemonade during the party which is approximately 24 ounces or 3/4 of a liter. Melissa can purchase lemonade in 2-liter bottles. How many bottles of lemonade will Melissa need?

In order to solve this problem, we must first determine how many liters of lemonade Melissa's guests will drink. Let's create a another formula based on the information provided to determine how much the guests will drink:

Amount of lemonade per person x Number of guests = Total amount of lemonade

0.75 x 11 = Total amount of lemonade

0.75 x 11 = 8.3

Melissa wants to have extra lemonade just in case some of her guests drink more lemonade than she anticipates, so she decides to round her estimate up. She would need to have 9 liters of lemonade on hand. Stores sell lemonade two-liter bottles, so Melissa must calculate how many bottles are needed. She would need to purchase:

Total number of liters / Number of liters per bottle = Total number of bottles

9 / 2 = Total number of bottles

9 / 2 = 4.5

Melissa needs 4.5 bottles of lemonade. Since she can't purchase a partial bottle, Melissa needs to purchase 5 two-liter bottles of lemonade for her guests.

## Determining the Cost of Items Needed

Now that Melissa has determined the quantity of food and drinks needed for her guests, she must calculate how much it will cost. Melissa determined that she needs 5 pizzas and 5 two-liter bottles of lemonade for her party.

In order to calculate the total cost, we need to determine the cost of the pizza and the cost of the lemonade separately. Let's start with the cost of the pizza. Melissa's neighborhood pizza shop sells an 8-slice pepperoni pizza for \$7.99. Since Melissa needs 5 pizzas, her total cost would be:

Number of pizzas needed x Cost per pizza = Total pizza cost

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