Arik bought 20 calculators at the electronics store. 40% of the calculators were scientific calculators and one half of the calculators were graphing calculators. How many neither scientific calculators nor graphing calculators

Ok lets grab our calculators!

Lets say Arik has 20 calculators at the store.

Lets multiply 20 x 40%

We should get 8

There is 8 scientific calculators

100 percent minus 40 percent is 60 percent

Lets multiply 20 x 60%

There is 12 graphing calculators

8 scientific calculators

12 graphing calculators

If you want to do this on paper or in your head

100 : 20 = 5

each calculator is 5 percent