Assertion: column's digit | /r/HasProperty | a 1
Facets:
value: over to the next column
type: OTHER
value: always
type: DEGREE
Source sentences:
text: Some pairs of digits add up to two-digit numbers, with the tens-digit always being a 1.
text: If the sum has two digits then write its last digit in the tens-column under the line, and carry its first digit (which should be a 1) over to the next column: in this case the hundreds-column.