What if a number keeps changing, or we don't know it yet? We use a LETTER to stand in for it — that's the first step into algebra!
🔡Letter-number: A letter (like a, n, x) used to represent a number that can change or is unknown.
📝Algebraic expression: A math phrase built with letter-numbers, like a + 3 or 2 × n.
✖️Dropping the × sign: We write 4 × n as just 4n — number first, then the letter, no × symbol needed.
🔁Substituting: To find the value, just replace the letter with a number. If a = 23, then a + 3 = 23 + 3 = 26.
📐Formulas: Expressions that describe a general rule, like "perimeter of a square = 4 × side".
Try thisShabnam is 3 years older than Aftab (age = a). If a = 23, Shabnam's age = a + 3 = 23 + 3 = 26 years
Start the challenge ↓