How to Quickly Square any 2-digit Number Mentally

December 19, 2017

| Specialist Math Tutor

 

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!

Practice LOTS to become really good at it!

Try squaring the following numbers and check with a calculator!

 

a) 41

b) 29

c) 37

d) 42

e) 38

f) 53

g) 69

h) 76

i) 67

j) 88

k) 94

l) 55

m) 73

n) 75

o) 19

 

 

Keep practicing and master this technique of squaring any 2-digit number quickly using mental arithmetic!

 

 

To get professional help (Math tuition) on secondary school mathematics in Singapore, click here.

 

 

 

Specialist Math Tutor

Mr Ausome

 

 

 

 

Please reload

Recent Posts
Please reload

Please reload

How to Avoid Making Careless Mistakes During Math Exams?

What Makes a Good Math Tutor?

O-level A-Math: Mastering Functions and Graphs (Part 2)

1/1
Please reload

© 2019 by APEX MATH TUITION SINGAPORE

  • Facebook Social Icon