Current location - Training Enrollment Network - Mathematics courses - I would like to ask the third grade mathematics in primary school: ABCD × 9 =DCBA, so what are the numbers represented by ABCD? Thank you!
I would like to ask the third grade mathematics in primary school: ABCD × 9 =DCBA, so what are the numbers represented by ABCD? Thank you!
The answer is a =1b = 0c = 8d = 9abcd =1089.

DCBA is still a four-digit number, so A must be 1, otherwise ABCD×9 is not a four-digit number.

The unit number of D×9 is 1, so d must be 9.

B should not be carried forward, so the choice of B is 0 or 1. If 1 is selected, there is C*9+8= 1, because if B= 1, C*9 cannot be carried forward, and 9C+8= 1 is invalid, that is to say, B=

The unit number of c× 9+8 is 0, so c is 8.

Get ABCD= 1089.

1089×9=980 1

Please don't make copies downstairs.