Wednesday, April 10, 2013

Decomposing Word Problems & a Freebie

In Math, we have been solving open-ended word problems where the students decompose numbers into two parts. We've been working our way through CRA (concrete, representational and abstract) and on these standards. CCSS.Math.Content.K.OA.A.2 Solve addition and subtraction word problems, and add and subtract within 10, e.g., by using objects or drawings to represent the problem. CCSS.Math.Content.K.OA.A.3 Decompose numbers less than or equal to 10 into pairs in more than one way, e.g., by using objects or drawings, and record each decomposition by a drawing or equation (e.g., 5 = 2 + 3 and 5 = 4 + 1).

Concrete - We love our part-part-whole plates. Not only are they divided into a big part and two small but you can write on them with dry erase marker again and again. Base ten blocks work great as counters. Sometimes, we in a circle and work with the partner next to us. But a great way to do this is with the document camera. After they decomposed the number on their plates, the Kinders come up to the board and touch the enormous projected plate. Each kinder gets to name the plate with an equation until we've named all 4 in the fact family. We also used the carrots and bunny mats here.

Representational - We use the part-part-whole mats included or draw them on the whiteboards. We get to draw and write the numeral in the first box. Then the students pick a counting on strategy to find the missing part. They "draw on" or hold it their head and count on their fingers.

We've just started talking about fact families. After we've solved for the missing number, we take turns touching the part-part-whole and saying the addition and subtraction equations. Then we check to see if all four have the same digits in them.

If you'd like the freebie, pick it up by April 13th. Comments welcome.
- Jenn

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