لكل وحدة رقم.

It is pronounced:

لِكُلِّ وَحْدَةٍ رَقَمٌ
li-kulli waḥdatin raqamun

If you pause at the end, the final -un is usually not pronounced, so you would say:

li-kulli waḥdatin raqam

لكل is made of two parts:

• لِـ = for / to
• كُلّ = every / each / all

So لكل literally means for every or for each.

In this sentence, that gives the sense of each unit has... or for each unit, there is...

In Arabic, short prepositions are normally written attached to the following word.

So:

• لِ + كُلّ → لِكُلّ

This is completely normal. You will see the same thing with other prepositions too, such as:

• بِ
  • word
• كَ
  • word
• لِ
  • word

Because after كلّ meaning every/each, Arabic normally uses a singular noun.

So:

• كلُّ طالبٍ = every student
• كلُّ وحدةٍ = every unit

Even though English often thinks of many items, Arabic treats them one by one after كلّ.

Because كلّ + singular indefinite noun is the common pattern for every/each + noun.

So:

• كلُّ وحدةٍ = every unit
• كلُّ كتابٍ = every book

If the noun were definite, the meaning would shift away from simple each/every and more toward all the... depending on the structure.

Because وحدة is in an iḍāfa construction with كلّ.

The structure is:

• كُلِّ وَحْدَةٍ

Here:

• كُلِّ is made genitive by the preposition لِ
• وَحْدَةٍ is the second part of the iḍāfa, so it is also in the genitive

That is why you get:

• لِكُلِّ وَحْدَةٍ

Because Arabic often expresses possession differently from English.

English says:

• Each unit has a number.

Arabic often says something more like:

• For each unit, a number exists
• To each unit belongs a number

So لِـ is doing the job that English often expresses with has.

This is a very common Arabic pattern.

A simple way to understand it is:

• لكل وحدة = a prepositional phrase, for each unit
• رقمٌ = a number

So the sentence literally works like:

For each unit, there is a number.

In traditional grammar, لكل وحدة can be analyzed as a fronted phrase, and رقمٌ as the delayed element being stated about it. But for a learner, the main point is:

• Arabic puts the for/to phrase first
• then gives the thing possessed: رقمٌ

Because the sentence is not talking about one specific known number. It is simply saying that each unit has a number.

So رقمٌ means:

• a number

If you said الرقم, that would mean:

• the number

which would sound more specific.

رقمٌ is in the nominative, which is why it takes ـٌ in full vocalization.

So the full form is:

رَقَمٌ

This is because it is the main noun being asserted in the sentence. In simple learner terms, it is the noun that completes the statement after لكل وحدة.

Yes, that is the literal shape of the Arabic.

But in natural English, you would usually translate it as:

• Each unit has a number.
• Every unit has a number.

So the literal form and the natural meaning are slightly different, even though they match grammatically.

Yes, وحدة is feminine.

In this sentence, that does not change much visibly, because there is no adjective or verb agreeing with it. But it matters for vocabulary and agreement in other sentences.

For example, if you added an adjective, it would need to be feminine too.

Yes. A more explicit alternative is:

كل وحدة لها رقم
Every unit has a number

This uses لها = it has / for it.

Both are understandable, but لكل وحدة رقم is shorter and more formal/compact in style.

Here رقم most naturally means number, especially an identifying number or assigned number.

It does not necessarily mean a single digit like 7. The exact meaning depends on context, but in a sentence like this, number/ID number is usually the best understanding.