Hi code detective, the puzzles are coming in thick and fast! Are you ready to try something new? These sequences involve both letters and numbers! The letters and numbers are joined together in a special order.

Here is the alphabet for you to use as a reference:

**A B C D E F G H I J K L M N O P Q R S T U V W X Y Z**

Look at the following letter and number pair sequence:

**A****1** is to **B****2** as **C****3** is to ______?

First, we need to work out how the first letter becomes the second letter.

The letters are moving one place to the right in the alphabet.

Now we need to work out how the first number becomes the second number. This happens by adding one each time.

So we need to add one letter to **C** and one number to **3** to get the missing pair of **D****4**.

So the answer is:

**A1** is to **B****2** as **C****3** is to **D****4**.

Let’s try another:

**C**4 is to** E****5** as **F****7** is to ______?

First, we need to work out how the first letter becomes the second letter.

The letters are moving two places to the right in the alphabet.

Now we need to work out how the first number becomes the second number. This happens by adding one each time.

So we need to add two letters to **F** and one number to** 7** to get the missing pair of **H****8**.

So the answer is:

**C****4** is to **E****5** as **F****7** is to **H****8**.

In this activity, you will need to be a sequence superstar to complete the number and letter pairs.

Pssstt!! Here’s a handy hint to help you reach superstar status:

Remember to use the alphabet line to help you work out the code.