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 = _.
The Number 10 and the Addition and Subtraction Concept
Big Idea:Understanding the meaning of the equal sign and finding missing addends to make equations true are the big ideas today. Students engage in conversation and activities to discuss their understanding and thinking.