Si el resultado no es exacto, la profesora dice que podemos redondearlo.

Because si here is the conjunction meaning if. In Spanish, si has no accent when it introduces a condition.

Compare:

• si = if
• sí = yes

So in this sentence, Si el resultado no es exacto... means If the result is not exact...

Resultado is a masculine singular noun, so it takes the masculine singular article el.

• el resultado = the result
• los resultados = the results

The article is used because we are talking about the result in a specific situation, not just the idea of results in general.

Because adjectives in Spanish usually agree with the noun they describe.

Here:

• resultado is masculine singular
• so the adjective must also be masculine singular: exacto

Examples:

• el resultado exacto
• la respuesta exacta

Profesora is the feminine form of profesor. It tells us the teacher is female.

• el profesor = the male teacher
• la profesora = the female teacher

Spanish often marks gender more clearly than English, where the teacher does not tell you whether the person is male or female.

Because Spanish normally uses que to introduce a subordinate clause after verbs like decir, pensar, creer, and similar verbs.

So:

• dice que podemos redondearlo = she says that we can round it

Leaving out que would be ungrammatical here.

Because this sentence uses the indicative, not the subjunctive.

After dice que, Spanish normally uses the indicative when the speaker is reporting something as a fact, statement, or normal instruction:

• dice que podemos... = she says that we can...

You would expect the subjunctive in other kinds of contexts, for example with doubt, denial, emotion, or certain expressions of influence.

Compare:

• Dice que podemos redondearlo. = She says we can round it.
• Duda que podamos redondearlo. = She doubts that we can round it.

Because redondear is an infinitive, and object pronouns can be attached to infinitives.

So:

• redondear + lo = redondearlo

Here lo means it.

This is very common in Spanish:

• hacerlo = to do it
• verla = to see her
• escribirlos = to write them

In this sentence, redondearlo means to round it.

Lo is the direct object pronoun, and it refers back to el resultado.

Since resultado is masculine singular, the matching pronoun is lo.

So:

• el resultado → lo

That is why we get:

• podemos redondearlo = we can round it

Yes. That is also correct.

With a conjugated verb plus an infinitive, the object pronoun can usually go in either place:

• podemos redondearlo
• lo podemos redondear

Both mean the same thing. The version with the pronoun attached to the infinitive is very common and often sounds slightly smoother, but both are natural.

Because Spanish often leaves subject pronouns out when they are not needed. The verb endings already tell you who the subject is.

Here:

• dice tells us it is he/she says
• podemos tells us it is we can

So Spanish does not need:

• ella dice que nosotros podemos redondearlo

That longer version is possible, but it would usually only be used for emphasis, contrast, or clarity.

Because it describes a real or general situation, not a hypothetical one.

The structure is:

• Si + present indicative, present indicative

So:

• Si el resultado no es exacto, la profesora dice que podemos redondearlo.

This suggests something like a general classroom rule or a normal instruction.

If you changed the tenses, the meaning would change too. For example:

• Si el resultado no fuera exacto... would sound hypothetical or less real.

Because the sentence begins with a conditional clause:

• Si el resultado no es exacto = if the result is not exact

When this kind of clause comes first, Spanish normally separates it from the main clause with a comma:

• Si el resultado no es exacto, la profesora dice...

This is similar to standard punctuation in English.

Yes, in this context it clearly means to round a number/result.

So redondearlo here means something like:

• round it
• round it off

Outside maths, redondear can sometimes have broader meanings depending on context, but in a sentence with resultado and exacto, the mathematical meaning is the natural one.