MATH MAGIC

MULTIPLYING TWO NUMBERS WHOSE DIFFERENCE IS 4.

Rule: Square the number midway between the two given numbers and subtract 4. Naturally the success of this short cut will depend on how easy it is to square a number. Example; Multiply 69 by 73. The number midway between the two numbers is 71. Check my previous post to know how to square any two-digit number ending in I. Applying this short cut, we find 71 x 71 = 5,041 and 5,041 - 4 =5,037 Therefore 69 x 73 = 5,037 Answer