Romans 4:10

In what circumstances? Was it after he was circumcised or before? Not after he was circumcised, but before;

1 Corinthians 7:18-19

If a man was circumcised when he was called, he must not try to alter it. If a man was uncircumcised when he was called, he must not have himself circumcised.

Galatians 5:6

For in union with Christ Jesus, neither circumcision nor the want of it counts for anything, but only faith acting through love.

Galatians 6:15

For neither circumcision nor the want of it is of any importance, but only a new creation.

Treasury of Scripture Knowledge

Summary

How was it then reckoned? when he was in circumcision, or in uncircumcision? Not in circumcision, but in uncircumcision.

Bible References

Not in circumcision

1 Corinthians 7:18
If a man was circumcised when he was called, he must not try to alter it. If a man was uncircumcised when he was called, he must not have himself circumcised.
Galatians 5:6
For in union with Christ Jesus, neither circumcision nor the want of it counts for anything, but only faith acting through love.
Galatians 6:15
For neither circumcision nor the want of it is of any importance, but only a new creation.