The Chinese words 算 (suàn), 算上 (suànshang) and 算了 (suànle) can be  quite easy to mix up because of their similarity. Getting similar things  confused in this way is called interference. The way to deal with this is to learn the differences as clearly as possible.

算 (suàn): to sum

Starting with the simplest of these words, let's have a look at 算. When used as a verb, 算 means “to sum” or “to calculate”.

Let's have a look at some example sentences for this meaning of 算:

我用计算器算出我的开支总额。

Wǒ yòng jìsuàn qì suànchū wǒ de kāizhī zǒng'é.

I totalled up my expenses with a calculator.

我要算算我今天一共花了多少钱。

Wǒ yào suàn suàn wǒ jīntiān yīgòng huāle duōshǎo qián.

I'm going to calculate how much money I've spent today.

我算了算，这次旅行要花大概一万块人民币。

Wǒ suànle suàn, zhè cì lǚxíng yào huā dàgài yī wàn kuài rénmínbì.

I've calculated that I'll spend about ten thousand RMB on this trip.

Another meaning of 算 as a verb is “to consider”, “to regard as” or “to count as”. Some examples:

他算得上一个作家。

Tā suàndé shàng yīgè zuòjiā.

He can be considered an author.

在花园走一走算不上锻炼！

Zài huāyuán zǒu yī zǒu suàn bù shàng duànliàn!

Taking a walk in the garden doesn't count as exercise!

那算得上道歉吗？

Nà suàndeshang dàoqiàn ma?

Does that count as an apology?

这算不了什么。

Zhè suànbuliǎo shénme.

This doesn't amount to much.

You could think of the basic, core meaning of 算 as “to calculate to be”. This ties together all of the different uses of 算.