Hong Kong
Find the sum of the greatest 4-digit and the smallest 4-digit number.
Answer:
10999
- The greatest 4-digit number can be formed by placing the greatest digit in the thousands, hundreds, tens, ones place. Thus, the greatest 4-digit number is 9999.
- Similarly, the smallest 4-digit number can be formed by placing the smallest digit in the thousands, hundreds, tens, ones place. However, then the number becomes 0000, i.e., 0, which is not a 4-digit number. Thus, we will place the next smallest digit (1) at the thousands place. Thus, 1000 becomes the smallest 4-digit number.
- Now, we need to find the sum of the of the greatest 4-digit and the smallest 4-digit number.
So,TTH TH H T O 9 9 9 9 + 1 0 0 0 1 0 9 9 9 - Hence, the sum of the greatest 4-digit and the smallest 4-digit number is 10999.
