Determine the smallest number that should be added to 1321 to make it divisible by 10.
A number is divisible by 10 if it has 0 in its ones place.
The ones digit of 1321 is 1.
After 1321, the smallest possible number that ends with zero is 1330.
Let x be the number that is added to 1321 to make it 1330 so that it is divisible by 10.
1321 + x = 1330
x = 1330 - 1321
x = 9.
Therefore, 9 should be added to 1321 to make it divisible by 10.