Clockwork Math

4th grade math strategies for unbelievably high scores on the Math Section of the SAT and ACT®

Once You Have Registered, Click Here for Access to Our Online SAT/ACT Prep University!

Sample Restricted Exchange™ Question

The average (arithmetic mean) of three different positive integers is 16.  If the first integer is 10 times as large as the second integer, what is the units digit of the largest possible value of the third integer?

a.  9

b.  7

c.  5

d.  4                                                                                                                       

e . Information cannot be determined based on the information given.

The Restricted Exchange is a huge category on the Math Section (typically 8 problems on the SAT, and 5 or 6 problems on the ACT).  They are all generally rated as difficult.  If you can not confidently work the problem in less than 90 seconds with 4th grade math skills, then you need  our program for score improvement.

Back to SAT Prep Course Page Back to Clockwork Math Parent's Page

You do not need a Paypal Account to Pay by Credit Card with Paypal

Only $79

US Orders Only

PayPal: Buy 5-Disk SAT Math DVD Series with Proprietary Syllabus, and 1 year unlimited forum access