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 = _.

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Possibilities are abound as students try to determine one of the possible solutions to a story problem. Although they won't be eating Apples and Bananas, Raffi would still be proud.

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Who doesn't love Laura Numeroff''s If You Give a Mouse a Cookie?! Connect to that well loved story and play a cookie themed game to practice start unknown subtraction problems.

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It's all in the family! In this lesson, students will build fact family "houses" by using 3 numbers and writing the related addition and subtraction sentences.

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Students understand counting on, but when we record our thinking do we have to record all. Of course not! This lesson is designed to get students to count on not all.

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Explorations of combinations! Two missing addend games and a story problem, focusing on finding combinations of 9, what else could a 1st grade teacher want.

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My First Graders have been studying many addition strategies. Now I want them to use these strategies to determine an unknown number in an addition equation.

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Incorporate dramatic play into your math block with this imaginative lesson! Students pretend they are taking orders in a bike shop-with each problem they have another missing part to find!

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It may not be Vegas, but this game will have kids thinking! Students use their understanding of missing parts to figure out if a number would fit any of their equations.

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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.