Senza la calcolatrice, Anna controlla i numeri a mano.

In Italian, it is very common to use the definite article with concrete nouns like tools and objects, so senza la calcolatrice is the most natural phrasing here.

• la calcolatrice = the calculator
• senza la calcolatrice = without the calculator / without a calculator, depending on context

Italian often uses the article where English might not focus on it much. Saying senza calcolatrice is not impossible in every context, but it sounds less standard here.

Italian usually leaves out subject pronouns when they are clear from the verb form.

• controlla already tells you the subject is he/she/it
• Since Anna is named, adding lei would be unnecessary

So:

• Anna controlla = Anna checks
• Lei controlla = She checks

In this sentence, Anna is enough.

Controllare is the infinitive, meaning to check.
In the sentence, the verb has to be conjugated to match the subject Anna.

Present tense of controllare:

• io controllo = I check
• tu controlli = you check
• lui/lei controlla = he/she checks
• noi controlliamo = we check
• voi controllate = you all check
• loro controllano = they check

Because the subject is Anna, Italian uses the third person singular form:

• Anna controlla

Usually, no. This is a very important false friend for English speakers.

In many cases, controllare means:

• to check
• to examine
• to verify

So here, Anna controlla i numeri means Anna checks the numbers, not Anna controls the numbers.

If you want the English meaning of to control in the sense of manage / be in command of, Italian often uses verbs like:

• controllare in some contexts
• gestire
• dominare

But in everyday sentences like this one, controllare is very often to check.

Italian often uses definite articles more than English does.

Here, i numeri means the numbers. Even if English might sometimes say just numbers, Italian usually prefers the article with plural count nouns in normal sentences.

So:

• controlla i numeri = checks the numbers

Without the article, controlla numeri, the sentence would sound unnatural in standard Italian.

A mano is an idiomatic expression meaning:

• by hand
• manually

So controlla i numeri a mano means Anna checks the numbers manually, not using a machine or device.

This is a set expression, so you should learn it as a chunk:

• fare a mano = to do by hand
• scrivere a mano = to write by hand
• controllare a mano = to check by hand

A learner might expect con la mano (with the hand), but that would not be the normal expression for manually in this context.

It is the present indicative.

In Italian, the present tense can cover several ideas that English often separates:

• Anna checks the numbers by hand
• Anna is checking the numbers by hand
• Anna checks the numbers by hand (habitually)

The exact meaning depends on context. On its own, this sentence could describe:

• a routine habit
• something happening now
• a general fact about how Anna does it

Italian word order is flexible, and putting senza la calcolatrice first gives it emphasis.

It highlights the condition first:

• Without the calculator, Anna checks the numbers by hand

A more neutral order would be:

• Anna controlla i numeri a mano senza la calcolatrice

That is possible, but the original sentence focuses first on the fact that the calculator is not being used.

The comma is natural because Senza la calcolatrice is an introductory phrase placed before the main clause.

So the sentence is divided like this:

• Senza la calcolatrice, = introductory phrase
• Anna controlla i numeri a mano. = main clause

In short sentences, Italian punctuation can sometimes be flexible, and you may also see:

• Senza la calcolatrice Anna controlla i numeri a mano.

But the comma helps readability and makes the structure clearer.

Because calcolatrice is a feminine noun in Italian, so it takes:

• la calcolatrice = the calculator

Its plural is:

• le calcolatrici = the calculators

There is no special logical reason you need to memorize here; noun gender in Italian is something you usually learn together with the word. So it is best to learn vocabulary as:

• la calcolatrice, not just calcolatrice

That way, you remember the gender automatically.