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    Subtracting across zeros.
    By linda2671

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    I'm a mentor for a new teacher, and I observed her teaching it this way. She draws three houses on the board. She puts one of her students' name on the house to the right. She put her name on the house in the middle, and my name on the house to the left. She put the numbers under the corresponding house. So with 203 - 158, she told her students that the student was wanting to bake cookies for her (his teacher), but he didn't have enough sugar, so he came to her house to borrow sugar. She didn't have any either, so she came to my house. I had plenty of sugar so I shared. I gave one of my two sacks of sugar to Miss ________. That gave her one sack to put in front of the zero. In order to share with her student, she had to take one cup away from hers. That left her with 9. Her student put that 1 in front of his 3. Now the student has 13 cups, his teacher has 9 cups and I have 1 cup. Now they can bake their cookies and take away as many cups as they need.
    I thought it was a little confusing, but her kids caught on very well.

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