Far out in the ocean, in the Great Coral Reef, there were four dolphins, Jade, Aurora, Caspir, and Amir. They wanted to throw a party for their friends.

Jade, being the most organized of the group, made a list of the people they needed to invite. She counted that there was a total of 8 guests.

Jade and Casper made another list of all the party supplies they would need: forks, plates, fish, and party hats.

Casper asked, "If I want each person to have one item, how many of each item on the list do we need to buy?"

Jade answered, "8, of course. We are inviting 8 dolphins, so we need 8 of each item." 

Casper said, "But wait! You didn't count Aurora, Amir, you, or me, so there should be 12 items."

Jade answered, "Right you are!" The two of them swam off to the Ocean Market to gather supplies.

Meanwhile, Aurora and Amir were planning out how to make sure everyone had a seat. Amir counted out 12 chairs. But Aurora ran into a problem. She only had 3 tables.

Aurora told Amir, "The party has to be cancelled! We won't be able to fit everybody!"

Amir replied, "I'm sure we can. Let's try!"

Aurora asked, "How many people will sit at each table?"

Amir replied, "I don't know. Let's start with 2 chairs at each table."

Aurora thought for a moment. Then, she exclaimed, "We can use addition to figure this out! If we use addition, how many chairs did we use if we put 2 at each table?"

Amir thought of this equation: 2+2+2. Aurora counted the number of chairs at the tables. They both found that they had used 6 chairs.

2+2+2=6

There's a faster way than starting over. Do you know what it is?

Wow, we still have a lot of chairs left. Let's start over. What if we have 3 chairs at each table?

"We could just add one more chair to each table, since there's already two chairs there, and 2+1=3."

Amir replied, "Great idea! Let's see how many chairs that will be in total!"

Aurora wrote in the sand "3+3+3" just as Amir finished moving the chairs, and they both exclaimed "9!"

3+3+3=9

Amir said, "That still isn't enough. Let's try 4 chairs at each table. Just like last time, we can add another chair to each table."