Math Challenge June 5

What percentage of the Earth's crust is made up of oxygen?

Clue: Earth's crust is made up of 28% silicon, 8% aluminum, and 17% other elements that are not oxygen.

Send answers to kellys3ps@sbcglobal.net
Parents may help, but try to let your child figure it out on their own.Weekly winner wins a Smencil. Monthly winner wins a $20 Barnes and Noble gift certificate!
Good Luck!
Kelly