Knowledge atom
Mentally subtract 10 from a number within 1000
Subtracts ten from any three-digit number without counting, including when the tens digit rolls back.
Start practiceProgress & proof summary
LifecycleNot started
Evidence progress0 of 1 pieces collected
0%Current predictionNo prediction yet
Why?Next reviewNot scheduled
Mastery projection: Not available yetWhat does this mean?
Standards alignment
2.NBT.B.8
Prerequisites
Common misconceptions
- cannot roll back across a hundred (205 − 10)
Required evidence
These evidence lanes define what would count toward this atom.
EvidencePerformanceStatusNext step
Recall itRetrieve the idea without a cue Not startedCollect one observation
Recent evidence
No evidence recorded yet
The first response record for this atom will appear here.