Why is it important to be able to do mental math?

Answer 1

There are a number of reasons for why mental math is helpful in everyday life.

• When paying with cash, being able to pay with amounts that return better change (If something costs $4.32 cents, and you pay $5.00, you'll get 68 cents back, however if you pay with $5.07, you'll get 75 cents back, which is just moreconvenient)
• When working in your first few jobs, you're going to have to deal with change fast. Even if the register tells you how much change to give back, sometimes they go down.
• Calculating a tip without a calculator.
• Keeping a rough estimate of how much you are spending while shopping, like a grocery store -- so the $150.00 total is not a shock to you.
• Just being able to rationalize, otherwise abstract concepts. Example, if you are running 5 miles, and you glance at your watch when you start and glance at your watch 30 minutes later you can calculate crude estimates of how much time and/or distance you have remaining. Otherwise, you'd only be able to say, "I've ran since whatever time I started and I have a lot left to run"
• Figuring how much sleep you are going to get if you go to bed at a certain time.

I could keep listing things, and go on and on, but the list is just arbitrary. The point is, there are justeveryday tasks where being able to do mental math makes life easier.

Academic Wise (and in many professions), mental math is even more important. Even with a calculator, computer models, etc. you will need to setup the problem or equation. And being able torecognizepatterns, that youestablisheddoing mental math for years, is, in some cases, the only way to setup the problem correctly.