How to Quickly Square any 2-digit Number Mentally
The above video by Mathemagician Art Benjamin shows an ingenious way of squaring any 2-digit numbers easily without a calculator. If you practice and master this technique, it serves as an amusing and fanciful trick to "show off" to you friends! Besides, it is also a good way to train your mental arithmetic skills.
Some examples that depicts his technique:
Pre-requisite to the trick:
You have to be proficient in multiplying a 2 digit by 1 digit number mentally.
Mathematics Behind it:
The math behind the technique is based on the "difference of 2 squares" identity that we learn in our secondary 2 math syllabus in Singapore.
Practice LOTS to become really good at it!
Try squaring the following numbers and check with a calculator!
Keep practicing and master this technique of squaring any 2-digit number quickly using mental arithmetic!
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