How to Multiply 2 Digit Numbers by 9 Really Fast

We have had several posts regarding lightning speed multiplication and in this post, we are going to learn another trick on how to multiply by 9. Note that this method is only possible if the ones digit is greater than the tens digit. How to Multiply 2 Digit Numbers by 9 Fast To get the […]

Month in Review – June 2015

Starting last month, at the end of the month, or the first week of the month, I will be reviewing the posts for the whole month. In this post, we review what we have learned so far last month, June 2015. June 2015 in Review – Summary of Posts Multiplication Algorithm Using Squares with Diagonals discusses lattice multiplication where you […]