Learn Hardcore Russian: Для студентов сделали скидку, поэтому сумма в счёте оказалась меньше. - They gave a discount for students, so the amount on the bill turned out to be smaller.

This is called an impersonal or subjectless construction. English often uses they or you in these situations; Russian simply omits the subject:

Мне посоветовали этот ресторан. – They recommended this restaurant to me.
Мне сказали прийти пораньше. – They told me to come earlier.

Why do we say сделали скидку and not something like имели скидку?

Russian uses specific verbs with скидка (discount). The natural collocations are:

сделать скидку – to give/make a discount
дать скидку – to give a discount
предоставить скидку – to grant/offer a discount (more formal/business-like)

Using иметь скидку (to have a discount) is unusual in this context when talking about a seller giving a discount. You might hear:

У меня есть скидка. – I have a discount (card, coupon, special rate).

But to say that someone gave a discount to someone, you say сделать / дать / предоставить скидку.

Why is скидку in the accusative case?

The verb сделать (to do/make) is transitive and takes a direct object in the accusative case.

Nominative: ски́дка (a discount)
Accusative: ски́дку

So:

сделали скидку = (they) made a discount / gave a discount

Other similar patterns:

сделать ошибку – to make a mistake
сделать подарок – to make/give a present
сделать работу – to do the work

What does поэтому do here, and why is there a comma before it?

Поэтому means therefore / that’s why / so. It introduces a result of the previous clause.

The sentence structure is:

Для студентов сделали скидку, – They made a discount for students,
поэтому сумма в счёте оказалась меньше. – therefore the total in the bill turned out to be smaller.

In Russian, when поэтому connects two clauses like this, you normally put a comma before it, because it separates two independent clauses:

Было холодно, поэтому мы остались дома. – It was cold, so we stayed at home.
Он опоздал, поэтому пропустил начало. – He was late, so he missed the beginning.

Why is it сумма в счёте, and not something like сумма на счёте?

Both в счёте and на счёте exist, but they refer to different things:

счёт as bill / invoice (in a restaurant, from a service, etc.):
- сумма в счёте – the amount in the bill/invoice
счёт as account (usually bank account):
- деньги на счёте – money in the account
- сумма на счёте – balance on the account

In your sentence, the meaning is clearly about a bill or invoice, so Russian chooses в счёте = in the bill.

Why does оказалась end in -ась? What does this form show?

Оказалась is the past tense, feminine, singular form of оказаться (to turn out, to turn up).

Infinitive: оказаться – to turn out to be
Masculine past: оказался
Feminine past: оказалась
Neuter past: оказалось
Plural past: оказались

It is feminine here because its subject is сумма (sum/amount), which is a feminine noun:

су́мма оказалась меньше. – the amount turned out to be smaller.

Russian past tense agrees with the gender and number of the subject.

What is the difference between оказалась меньше and была меньше?

Both can be translated as was smaller, but there is a nuance:

была меньше – was smaller (neutral, simple statement)
оказалась меньше – turned out to be smaller (there is a sense of result or maybe slight surprise / outcome)

In this sentence, оказалась меньше suggests:

after calculating the bill (taking the discount into account),
the resulting amount turned out to be smaller than expected.

So it emphasizes the result of a process (the discount being applied), not just a static fact.

Why do we use меньше alone and not something like меньшей?

Меньше here is a comparative form (of малый / мало) and is being used predicatively (as part of what is said about the subject, not directly modifying a noun).

су́мма ... оказалась меньше. – the amount turned out (to be) smaller.

In this structure, Russian normally uses the short comparative (меньше, больше, лучше, хуже, etc.) without agreeing in gender/case.

Compare:

Сумма оказалась меньше. – The amount turned out to be smaller.
Сумма оказалась ме́ньшей. – Grammatically possible but sounds literary/marked; more often used when followed by something:
- Сумма оказалась меньшей, чем мы ожидали. – The amount turned out to be smaller than we expected.

In everyday speech, меньше alone is the most natural choice.

How do you pronounce счёте, and why is there ё instead of е?

Счёте is pronounced approximately as [що́-те], but with the Russian щ sound (long, soft "sh" sound).

счёт – [щот]
в счёте – [ф що́-тʲе]

The letter ё in Russian always carries stress and is pronounced like “yo” in “york”:

счёт – shchyot (bill, invoice, account)
счёте – shchyó-t’e (prepositional case: in the bill)

Often, Russians write е instead of ё in normal texts (e.g. счете), but the pronunciation is still ё. In learning materials, ё is usually written to show correct pronunciation.

Why is счёте in the prepositional case?

The phrase в счёте uses the preposition в (in). When it means “in / inside”, в normally requires the prepositional case.

Nominative: счёт (bill)
Prepositional: в счёте (in the bill)

Other examples:

в книге – in the book
в газете – in the newspaper
в отчёте – in the report

So сумма в счёте literally is “the amount in the bill”.

Could we change the word order, for example say Сделали скидку для студентов? Would it change the meaning?

Yes, you can say:

Сделали скидку для студентов, поэтому сумма в счёте оказалась меньше.

This is also correct and means the same thing. The difference is only in focus and style:

Для студентов сделали скидку
– Slightly emphasizes “for the students” at the beginning.
Сделали скидку для студентов
– Slightly emphasizes the action (made a discount) first, then specifies for whom.

Both word orders are natural, especially in spoken Russian. The original one just foregrounds the group benefiting from the discount.

Is there a reason the sentence uses сумма в счёте, not just счёт оказался меньше?

Both are possible, but they’re not identical in nuance:

сумма в счёте оказалась меньше – focuses on the amount (the numerical total).
счёт оказался меньше – focuses on the bill as a whole (as a concept: the bill, the check).

In many situations they are interchangeable, but:

If you specifically want to talk about the total amount of money, сумма в счёте is more explicit.
In casual speech people very often say счёт оказался меньше / больше, чем мы думали.

So the sentence as written slightly highlights the sum/total, not just the bill itself.