Question

When this 3-digit number is rounded to the nearest hundred it rounds down to 600. The digit in the ones place is the third odd number that you count beginning with 1. The sum of the digits is 13. What is the number?​

Answer 1

625

Explanation:

Firstly, I found the ones place because I just needed to know the third odd number starting from 1. The first odd number is 1 then 3 and then 5, so I know that the digit in the ones place is 5.

Ones place: 3rd odd number: 1, 3, 5

Then, I looked at the hundreds place, because I know that it is rounded to down to 600 in the nearest hundred, I know it has to be 649 or smaller and bigger than 600. In the range of 600-649, the hundreds place remains the same, and therefore I know that the digit in the hundreds place is 6

Finally, to determine the tens place, I can do 13-(6+5) I can do this because I know that the sum of the digits is 13. Because 13-11=2, I know that the digit in the tens place is 2

Final number: 625

Answer 2

1. rounds down to 600 = 601 - 649

2. The digit in the ones place is the third odd number that you count beginning with 1. = 605

3. The sum of the digits is 13