You may have seen these riddles that pop up on Twitter, LinkedIn, or other social media. Some are mildly interesting, some weird or no fun at all, and occasionally, they’re quite intriguing. This one keeps circulating—and no one seems to agree on the right answer:

“What is the correct answer: 8 ÷ 2 (2 + 2) = ?”

There are two camps, and neither wants to give in. The answer is either 1 or 16.

The basic math rules are learned at school, and in most cases, you’ve learned a so-called ‘mnemonic’ (an ass’ bridge, or ezelsbruggetje, as it’s called in Dutch), helping you to understand how a math challenge should be solved. The problem in this case? There seem to be different rules as to what comes first: division or multiplication?

We all agree on the first step: solve inside the brackets. That’s the easy part: 2 + 2 = 4. The next step is where things get tricky. Some say you go from left to right, so division comes first and multiplication second:

8 ÷ 2 = 4, then 4 × 4 = 16.

Traditionalists stick to the order of their mnemonic: PEMDAS or BODMAS.

  • PEMDAS = Parentheses, Exponents, Multiplication, Division, Addition, Subtraction

  • BODMAS = Brackets, Orders, Division, Multiplication, Addition, Subtraction

The PEMDAS crowd might do multiplication first (2 × 4 = 8), then division (8 ÷ 8 = 1). But others argue that multiplication and division are on the same level and should be performed left to right—bringing us back to 16.

BODMAS seems to support 1 as well: brackets first (2 + 2 = 4), then 2 × 4 = 8, then 8 ÷ 8 = 1.
But again, once the brackets are gone, the order of operations reverts to division–multiplication, which can lead to 16.

It’s confusing.
It’s messy.
And it’s math.

Thankfully, I’m a VAT person—not a mathematician.
But isn’t it comforting to know that VAT isn’t the only system where multiple answers to the same question are possible? Even in a discipline like math—where there’s always supposed to be a single answer, even if it’s buried in decimals—uncertainty still creeps in. We’d celebrate that with a piece of pi(e).

VAT has its own logic, its own rules—and, crucially, its own order of operations. While there may not be a universally accepted acronym, many VAT professionals follow an informal step plan to approach a VAT question—often referred to as the “VAT decision tree” or simply the “7 W’s”:

  • Who is the taxable person?

  • What is being supplied—goods or services?

  • Where is the place of supply?

  • When does VAT become due?

  • What is the taxable amount?

  • What VAT rate or exemption applies?

  • Who is liable to report/pay the VAT, and how must it be reported (invoicing, returns, formalities)?

  • (Bonus step: Can input VAT be recovered?)

This might seem straightforward. But—as with PEMDAS—changing the order can change the outcome.

For example, if you determine the place of supply before assessing whether you’re dealing with goods or services, you might end up applying the wrong country’s rules. Or if you skip ahead to the rate before correctly identifying the nature of the supply, you could apply a reduced rate where it doesn’t belong—or miss one where it does.

And input VAT? If you skip straight to the “who and how” without asking whether the input relates to taxable or exempt output, you might be celebrating too early (or worse: reclaiming too much).

Just like in math, sequence matters.
But unlike math, VAT has an extra twist: interpretation.
Different tax authorities, judges, and even colleagues may apply the steps in different ways. Some inspectors prioritize form over substance. Others emphasize economic reality. One insists on proper invoicing, another waves it away in favor of intention.

In the end, it’s all about clarity and consistency—and knowing which rules you’re playing by.

And when in doubt?
It’s always good to go back to the basics, double-check your brackets, and never divide your attention when multiplying VAT complexity. Keep it simple.