WHAT CAN I DO WITH THE ANTIQUE PHONE IN THE KITCHEN?

Not call anyone, we're afraid.

But that looks like a nice pen.

Tap the pen to open a little note drawer, and read the note.

Looks like you need to work out the numbers represented by the symbols: square, triangle, diamond, star.

Let's take them one by one. In the first one, you have the word ROOT inside a square.

Square root.

Like 2 is of 4.

So the missing number must be the number that 3 is the square root of.

The second riddle seems to be a sequence. What connects the numbers in the sequence?

The clue is in the name.

ADDie's.

You add each number with the previous one to get the next one.

What number added to 1 will give you 5, and added to 5 will give you 9?

In the third riddle, the word PRIME is underlined.

41 is a prime number. The other two-digit number ends in 5.

There's only one way this can be a prime number.

In the fourth puzzle, you're dealing with handstand twins.

They look identical when one of them is upside down, like 6 and 9.

What's the handstand twin of 8?

(SOLUTION FOLLOWS)

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The answers put together are 9408.

Close the notes and dial this number on the antique phone. Get two hidden articles as your reward.