Can you solve these simple math problems without a calculator?

Calculators are so incredibly useful. But what do you do if you don't have one on hand? Oh yeah: Your brain is a calculator come to life. Can you solve the following problems with only the help of your grey cells? Find out and compete with your friends.

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
To warm up: 55 + 4 =

apost.com