So close, but the correct answer is 83.

I recommend reading Volume 1 of the Learn Math Fast System.  That book will quickly teach you how to add, subtract, multiply and divide numbers in your head.  Plus, you'll learn a lot of cool tricks to make math easier to solve.  Don't worry about going back to volume 1, older students can complete it in about a month.  Younger students will need more time, but whatever age you are, you'll become a math whiz after reading that book.  Use the coupon code PT2026 to get 10% off your order.