1st Grade 1.OA.B.4 Math Operations Algebraic Thinking Printable Worksheet PDF. Common Core State Standard 1.OA.B.4 Understand subtraction as an unknown-addend problem.
1st Grade 1.OA.B.4 Math Operations Algebraic Thinking Printable Worksheet PDF. Common Core State Standard 1.OA.B.4 Understand subtraction as an unknown-addend problem.