Correspondence involves two or more connected items. In mathematics, correspondence problems are used to find the total number of combinations which can be made between connected things.

Listing combinations

Tables are used to identify all the possible combinations which can be made between groups of items, in order to solve correspondence problems.

Example 1

Vanessa has $3$ fruits and $2$ desserts. She would like to have $1$ of each. What combinations of fruit and dessert can Vanessa have?

Fruit

Dessert

Grapes

Chocolate

Apple

Chocolate

Tomato

Chocolate

Grapes

Doughnut

Apple

Doughnut

Tomato

Doughnut

Count the total number of combinations or rows in the table.

There are six different combinations of fruit and dessert Vanessa can make.

Note: Find all the combinations that can be made with one item first, then move onto the next item.

Correspondence problems using multiplication

Sometimes, in correspondence problems, there are too many combinations to list in a table. Instead, multiplication can be used to find the total number of combinations.

Example 2

Ronaldo wants a drink and a snack. He can choose from $5$ drinks and $3$ snacks. How many combinations of drinks and snacks can be made?

There are $5$ drinks.

Each drink can be paired with $3$ different snacks.

This means, there are $5$ lots of $3$ combinations between drinks and snacks.