Critical Analysis & Evaluation
📋 What it is
Check a solution by substituting it back; spot where a worked solution went wrong.
🗣️ Coach says
Solving is half the job — checking is the other half. Substitute your answer back into the ORIGINAL equation: if both sides match, you're right. Finding someone else's error sharpens your own accuracy.
🧠 Memory hook
CHECK by substituting back. If the two sides aren't equal, hunt for the slipped step.
😂 Giggle
What did the algebra textbook say to the student?
"I've got a lot of problems — can you help me solve them?"
😲 Whoa!
Professional coders spend more time checking and fixing than writing — "does the answer actually work?" is the real skill.
✅ Quick check: You solved x + 5 = 12 and got x = 8. Check it — is it right?
Say your answer out loud first — then reveal.
No: 8 + 5 = 13, not 12. The correct answer is x = 7.
Substituting back reveals the error; 7 + 5 = 12 checks out.
🧪 Try it! (2 minutes)
Solve any two-step equation, then substitute your answer back to prove it works.