This is a numeric palindrome -- spelled (or in this case numbered) the same way forward and backward.
zero
1234567890 + 4563217890 = 5797785780
456789 * 1234567890 = 5.63937032 × 1014
The answer is 1.8253374e+18
1,219,326,311,126,352,690
This is a numeric palindrome -- spelled (or in this case numbered) the same way forward and backward.
2222222211
To round to the nearest 100, look at the 10s digit to decide whether to round up or down. The 10s digit of 6963 is 6 which is 5 or more, so round up: 6963 → 7000 to the nearest hundred.
To convert any decimal to percent you just multiply by 100. In this case, 400,100 × 100 = 40,010,000%
1234567890
2469135780
zero
1.52415788 × 1018
1234567890-1234567856 = 34
1 plus 1234567890 is 1234567891
1234567890+9876543210=11,111,111,100