Checking for careless mistakes using the Substitution Method

• Normal method of checking (i.e. check your working from front to back again), may or may not find the error
• Using Substitution Method of checking guarantees that your answer is correct, and will find an error if there is one.
• Use  Substitution Method of checking for all algebra/solving/simplify questions worth 2 marks or more. You will be able to save many many marks using this method!
• Only takes 10 seconds with practice. (use calculator)

Example (using substitution method)

Express as a single fraction in its simplest form. [2 marks]

After getting your answer (), you can substitute in the value .

When, , , and

Since both expressions give the same value, you have just checked that your answer is correct!

Author: mathtuition88

https://mathtuition88.com/ View all posts by mathtuition88