رقم الاوضة اربعة.

A common Egyptian pronunciation is roughly:

ra'm el-ōDa arbaʿa

A few notes:

• رقم is often pronounced ra'm in Egyptian, because ق is usually pronounced like a glottal stop ء in Cairene speech.
• الاوضة / الأوضة is pronounced el-ōDa or il-ōDa.
• أربعة is pronounced arbaʿa.
• The ض in أوضة is a heavy/emphatic d sound, not a plain English d.

So the whole sentence sounds something like:

ra'm el-ōDa arbaʿa

Because Arabic often leaves out the verb to be in the present tense.

So in Egyptian Arabic, a sentence like:

رقم الأوضة أربعة

literally looks like:

room number four

but naturally means:

The room number is four.

This is very normal in Arabic.
If you wanted a past tense, then a verb would appear, for example with كان (was).

Yes. أوضة means room in Egyptian Arabic.

With ال-, it becomes الأوضة = the room.

This word is colloquial Egyptian. In Modern Standard Arabic, the more common word is:

غرفة = room

So:

• الأوضة = Egyptian Arabic
• الغرفة = Standard Arabic / more formal

In careful spelling, many people would write:

الأوضة

But in everyday informal writing, especially in dialect, people often leave out the hamza spelling details and write:

الاوضة

So both are common in practice, but الأوضة is the more careful spelling.

This happens a lot in casual Arabic writing, especially with dialect words.

Literally, it means:

the number of the room

Arabic often builds this kind of phrase by putting two nouns next to each other:

• رقم = number
• الأوضة = the room

So:

رقم الأوضة = the room’s number / the number of the room

Then أربعة gives the value of that number.

This is a simple nominal sentence in Egyptian Arabic:

• رقم الأوضة = the subject/topic
• أربعة = the predicate/comment

So the pattern is basically:

[thing being talked about] + [what it is]

Here:

• رقم الأوضة = what you are talking about
• أربعة = what you say about it

That is why the sentence feels very compact.

Because أربعة is the usual standalone form for four.

In this sentence, the number is not directly counting a noun. It is being used as the value of a label or number, like a room number.

So this is similar to saying:

• My number is four
• The bus number is four
• The room number is four

In that kind of use, Arabic simply gives the numeral itself.

Not in an important way for this sentence.

Arabic numbers can behave in complicated ways when they directly count nouns, but here أربعة is just being used as a standalone number value, not as a counting word before a noun.

So for a beginner, the safest way to understand this sentence is:

• أربعة here simply means four
• you do not need to worry much about number-gender rules in this specific example

That final letter is ة (taa marbuuTa).

In Egyptian Arabic, when a word ends there and you stop after it, it is usually pronounced as -a.

So:

• أوضة sounds like ōDa
• أربعة sounds like arbaʿa

In connected grammar situations, that ة can sometimes act differently, but for everyday pronunciation, -a is the main thing to remember.

No. Egyptians also very commonly use:

نمرة = number

So you may also hear:

نمرة الأوضة أربعة

This means the same thing.

Both are used, but نمرة feels especially common in everyday Egyptian speech.

Yes, sometimes Egyptians say things a bit differently, for example:

الأوضة رقمها أربعة

Literally: The room, its number is four.

This is also natural.
But your original sentence:

رقم الأوضة أربعة

is perfectly good and clear.

No, not for Egyptian Arabic.

In Egyptian Arabic, the case endings used in formal Standard Arabic are not normally pronounced in everyday speech. That is why the sentence is short and simple:

رقم الأوضة أربعة

No extra endings are needed in normal Egyptian pronunciation.