## CCSS.Math.Content.1.OA.D.8 - Determine the unknown whole number in an addition or subtraction equation relating three whole numbers. For example, determine the unknown number that makes the equation true in each of the equations 8 + ? = 11, 5 = ? - 3, 6 + 6 = ?.

Authors: National Governors Association Center for Best Practices, Council of Chief State School OfficersTitle: CCSS.Math.Content.1.OA.D.8 Determine The Unknown Whole Number In An Addition Or Subtraction... Operations and Algebraic Thinking - 1st Grade Mathematics Common Core State Standards

Publisher: National Governors Association Center for Best Practices, Council of Chief State School Officers, Washington D.C.

Copyright Date: 2010

(Page last edited 10/08/2017)

- I4C: Online Practice - Determine the unknown number in each equation - These online practice quizzes (interactives) support the following Common Core State Standard: CCSS.Math.Content.1.OA.D.8. There are 100 quiz sets available on this topic. Answers are corrected after each question and a quiz results page is also shown which can be printed or emailed to a teacher, parent or mentor.
- I4C: Online Practice - Determine the Unknown Number in the Addition Equation (up to 20) - These online practice quizzes (interactives) support the following Common Core State Standard: CCSS.Math.Content.1.OA.D.8. There are 100 quiz sets available on this topic. Answers are corrected after each question and a quiz results page is also shown which can be printed or emailed to a teacher, parent or mentor.
- I4C: Online Practice - Determine the Unknown Number in the Addition or Subtraction Equation (up to 20) - These online practice quizzes (interactives) support the following Common Core State Standard: CCSS.Math.Content.1.OA.D.8. There are 100 quiz sets available on this topic. Answers are corrected after each question and a quiz results page is also shown which can be printed or emailed to a teacher, parent or mentor.
- I4C: Online Practice - Determine the Unknown Number in the Subtraction Equation (up to 20) - These online practice quizzes (interactives) support the following Common Core State Standard: CCSS.Math.Content.1.OA.D.8. There are 100 quiz sets available on this topic. Answers are corrected after each question and a quiz results page is also shown which can be printed or emailed to a teacher, parent or mentor.
- I4C: Printable Worksheets - Determine the unknown number in each equation - These worksheets support the following Common Core State Standard: CCSS.Math.Content.1.OA.D.8. There are 100 worksheets available on this topic. A master answer key is available.
- I4C: Printable Worksheets - Determine the Unknown Number in the Addition Equation (up to 20) - These worksheets support the following Common Core State Standard: CCSS.Math.Content.1.OA.D.8. There are 100 worksheets available on this topic. A master answer key is available.
- I4C: Printable Worksheets - Determine the Unknown Number in the Addition or Subtraction Equation (up to 20) - These worksheets support the following Common Core State Standard: CCSS.Math.Content.1.OA.D.8. There are 100 worksheets available on this topic. A master answer key is available.
- I4C: Printable Worksheets - Determine the Unknown Number in the Subtraction Equation (up to 20) - These worksheets support the following Common Core State Standard: CCSS.Math.Content.1.OA.D.8. There are 100 worksheets available on this topic. A master answer key is available.
- Ace of Numbers - Interactive online game; find the card that completes the number sentence.
- Complete Subtractiion Sentence. - Fill in the missing number.
- En Garde Game - This is an addition equations balancing equations game. The player answers the question and duels. (some may find this a bit too violent)
- Missing Addend - Online matching game; match missing number to its correct value.
- Missing Number - Find the missing number in these addition problems.
- Missing numbers - Online game; fill in the missing number. Can set parameters in this game.
- Secret Number - Online game; click on the missing number.
- What number would complete this sentence - Online game; fill in the missing number.
- Word Problems - Unique worksheet; have students enter their own numbers on the sheets then swap with another student.