TalentJR apps
Ask a friend to pick two small numbers and write them down. Each next number is the sum of the two before it — a leapfrog list — until there are 10 numbers. You glance at the list and say the total at once: it is always 11 times the 7th number!
✓ You passed this trick’s test.
Seventh times eleven — “in a leapfrog list of 10 numbers, the total = 11 × the 7th number”
Use it for: A show-stopper magic trick for family and friends, and practice for adding long lists and spotting number patterns.
Check: 2 + 5 + 7 + 12 + 19 + 31 + 50 + 81 + 131 + 212 = 550 ✓
Work it out in your head or on paper, type the answer and press Check. Stuck? Press “Show me how”.
Right: 0 · Tried: 0
20 questions. Check each answer, then go to the next one. Get 16 or more right to pass.
🏅 Sign in with Google to earn the 🐸 Leapfrog Legend badge when you pass — and a certificate when you finish all 10 tricks of Part 4 · Clever counting & checking. 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.
Prefer a real teacher? TalentJR teachers take live online classes anywhere in India and visit homes in selected cities. Tell us what you need and our team will call you with timings and fees.