🧪 Mini Periodic Table — 10 elements
Tap a tile to learn its symbol, name, atomic number (Z) and a fun fact.
Z = number of protons
Element: —
Symbol: — · Z=—
Select a tile.
➕ (a + b)² = a² + 2ab + b²
Use sliders to change a and b. Colored regions show a² (cyan), 2ab (magenta stripes), b² (green).
(a+b)² = a² + 2ab + b²
a²=— · 2ab=— · b²=— · sum=—
✖️ Multiplication Shortcuts
Play with 9×, 11× (two digits), and squaring numbers ending in 5.
9× → digits sum to 9 · 11×AB → A (A+B) B · (10k+5)² → 100k(k+1)+25
9×7 = 63 · digits 6+3=9
34 × 11 = 374
65² = 4225 · rule: 6×7=42 → 4225