Lessons for 3.NBT.A.2
Counting up to find a differenceStarting at the smaller number and adding on until the larger one is reached.Lesson
Multi-digit additionAdd by place value, regrouping when a column passes nine.Lesson
Multi-digit subtractionSubtract by place value, regrouping when a column runs short.Lesson
The partial sums methodAdding each place on its own and then combining the parts.Lesson
Regrouping in additionTen ones become one ten so that no place ever holds more than nine.Lesson
Regrouping in subtractionOne ten is broken into ten ones when a place does not have enough.Lesson
The standard addition algorithmAdding column by column from the right and carrying into the next place.Lesson
The standard subtraction algorithmSubtracting column by column from the right, unbundling where needed.Lesson
Subtracting across zerosDifferences where the places being borrowed from hold nothing.Lesson
Printable Worksheets
Counting up to find a difference worksheet (PDF)Printable worksheet with answer keyPreview
The partial sums method worksheet (PDF)Printable worksheet with answer keyPreview
Regrouping in addition worksheet (PDF)Printable worksheet with answer keyPreview
Regrouping in subtraction worksheet (PDF)Printable worksheet with answer keyPreview
The standard addition algorithm worksheet (PDF)Printable worksheet with answer keyPreview
The standard subtraction algorithm worksheet (PDF)Printable worksheet with answer keyPreview
Subtracting across zeros worksheet (PDF)Printable worksheet with answer keyPreview