Lessons for 1.OA.D.8
Parts, wholes and number bondsKnowing every pair of whole numbers that adds to ten.Lesson
Subtraction as an unknown addendTaking away and finding the missing part are the same question.Lesson
Finding the missing number in an equationThe missing number in an addition or subtraction equation, wherever it sits, is found by asking what makes both sides the same.Lesson
Printable Worksheets
Parts, wholes and number bonds worksheet (PDF)Printable worksheet with answer keyPreview
Subtraction as an unknown addend worksheet (PDF)Printable worksheet with answer keyPreview
Finding the missing number in an equation worksheet (PDF)Printable worksheet with answer keyPreview