TalentJR apps
Identities are true for every value of the letters: (a + b)² = a² + 2ab + b², (a − b)² = a² − 2ab + b² and (a + b)(a − b) = a² − b². They make mental maths easy: 103² = (100 + 3)² = 10000 + 600 + 9 = 10609, and 53 × 47 = (50 + 3)(50 − 3) = 2500 − 9 = 2491.
✓ You passed this lesson’s test.
Split into easy parts — “write a hard number as a round number plus or minus a small one”
Use it for: Quick multiplication in your head, checking long multiplication, and the algebraic expressions and identities chapter of Class 8 maths.
Check: 53 × 47 = 53 × 40 + 53 × 7 = 2120 + 371 = 2491 ✓
▶ Watch it animatedWork it out in your head or on paper, type the answer and press Check. Stuck? Press “Show me how”.
Right: 0 · Tried: 0
20 sums. Check each answer, then go to the next one. Get 16 or more right to pass.
🏅 Sign in with Google to earn the 🪄 Identity Wizard badge when you pass — and a certificate when you finish all 8 lessons of Part 8 · Class 8. You can still take the test without signing in.
Why does it work? When should you use it? Ask in English, मराठी or हिंदी.
Sign in with Google to ask Free — 20 questions a day.
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