Directions: Using the digits 1 to 9, at most one time each, fill the boxes below to create the smallest possible difference.

### Hint

Remember that zeros are not allowed. Because you can only use each digit once, the digit in the hundreds place can’t be the same.

### Answer

14

One possible solution is 612-598 = 14.

Source: Graham Fletcher

We also got 14 with 412-398=14.

Nice!

999-987

But you used 1 in the question and 1 in the answer.

The answer isn’t included in the digits being used once, since it says “fill the boxes”.

My best is 718-695 = 23

612-598=14.

612-598=14

612-598 = 14

612-598=14

612-598=14

612-598=14

412-398=14

512-498=14

512-498=14

My best is 701-698=3

You cannot use the number 0

516-498=18

You cannot use the number 0 in the problem.

612-598=14

516-498=18

612-598=14

612-598=14

987-987=0

you can’t repeat the same numbers

102-96=2

So no repeating numbers and no zero and the answer is fine.

Well no using the same numbers twice.

Smallest difference is 14. Possible combinations are: 812-798, 712-698, 612-598, 512-498 and 412-398.

Largest difference is 987-123=864

Largest difference – so you can have repeat numbers in the problem and in the answer?

976-853=123

912-865=47

123-987= -864