Repdigit Addition” or “Repunit Addition” : Ex 3: 1+11+111+1111+11111 = ?, Ex 4: 2+22+222+2222+22222 = ? Ex 5: 3+33+333+3333=?


Rule: Counting 1 Addition Rule
Count how many times "1" appears in the given numbers. Then, write the counting sequence from 1 up to that number. The rule is based on "1", but if the number changed "2 or 3 or 4 etc ". in that case Multiply by repeated no.


Ex 1: 1+11 = ?



  • "1" appears twice.

  • So, we write numbers from 1 to 2.

  • Answer: 12


Ex 2: 1+11+111+1111 = ?



  • "1" appears four times.

  • So, we write numbers from 1 to 4.

  • Answer: 1234


Ex 3: 1+11+111+1111+11111 = ?



  • "1" appears five times.

  • So, we write numbers from 1 to 5.

  • Answer: 12345


Ex 4: 2+22+222+2222+22222 = ?



  • The rule is based on "1", but here we have "2".

  • If we follow the pattern, we count from 1 to 5.

  • Multiply by repeated no. Here 2 is repeated no.

  • Answer: 12345 x 2 = 24690 (but this needs clarification for numbers other than "1").


Ex 5: 3+33+333+3333=?



  • This rule is designed for "1", but we have "3" here.

  • If applied in the same way, the answer would be 1234 × 3 = 3702.