math problem

Math problems can go viral on social media when people start getting different answers. Especially, nowadays, in the age of the Common Core. On occasion, there can be some heated arguments as some of us who are older were taught math a different way. Nonetheless, they can be a nice break from the gossipy and political arguments we’re bombarded with online.

Take the equation below, for example.

7 + 7 ÷ 7 + 7 × 7 – 7 = ?

Can you figure this out? It’s not as simple as calculating from left to right. You have to break it down further.

Mathematician and Economist Presh Talwalkar breaks this equation down for us by explaining it in dollars.

Start out with $7.

The next part  7 ÷ 7 needs to be broken down rather than just adding and then dividing to the first number in the problem.  7 ÷ 7 is one, so add $1 to the original $7. You now have $8. 

+ 7 × 7 comes next. Multiplying those numbers together gets you $49. Adding that to $8 gives you $57.

The last part is – 7. Subtracting $7 from $57 leaves us with $50.

The answer is, therefore, $50.

You can watch Presh Talkwalker explain how to answer this problem in the video below.

Today, they teach the order of operations. PEMDAS/BODMAS is an acronym for the way the order of operations is currently taught. This means you first evaluate Parentheses/Brackets, then evaluate Exponents/Orders, then evaluate Multiplication-Division, and finally evaluate Addition-Subtraction.

This same problem is solved without using money below:

7 ÷ 7 = 1
7 × 7 = 49

This means

7 + 7 ÷ 7 + 7 × 7 – 7
= 7 + 1 + 49 – 7

Now we can evaluate the addition and the subtraction from left to right.

= 8 + 49 – 7
= 57 – 7
= 50

It’s obviously the same answer. It’s just written out in a different format.

Doing viral math problems like these are a good way to keep your mind sharp. These aren’t problems we encounter in everyday life, at least not written out in a format such as this. It’s helpful to flex your brain and solve some of these problems. And it is even better if you learn something in the process. Never stop learning!

Share this if you got the problem right!

Source: Mind Your Decisions

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