489967234+500101234+657999812,correct upto the nearest ten thousand

Answer 1

489967234 + 500101234 + 657999812 = 1648068280

To round numbers to the nearest ten thousand, make the numbers whose last four digits are 0001 through 4999 into the next lower number that ends in 0000.

For example 54424 rounded to the nearest ten thousand would be 50000.

Numbers that have the last four digits of 5000 through 99999 should be rounded up to the next even ten thousand.

For example 78988 rounded to the nearest ten thousand would be 80000.

In this case 1648068280 become 1648070000 when it rounded to the nearest ten thousand.

Answer 2

1648068280
1,648,068,280 (always separate from the back in groups of 3 - this number is over 1 billion!)

To the nearest ten thousand is 1648070000, I believe.