Chapter 6 · Equations · page 31 of 68
Check by substitution
levelGrade 6
standard6.EE.B.5
practiceTwo-step equations
An answer to an equation can always be checked: put it back in for the variable and see whether both sides come out equal. If they do, it is right. If not, something slipped, and you know before anyone else does.
How to use it
- Replace every variable with your answer.
- Work out each side separately using order of operations.
- Compare. Equal means correct.
Example
Where it goes wrong
- Checking only one side.
- Not checking at all. It takes ten seconds and it catches almost every sign error.