ORC Lesson Plan

The grade for this lesson plan is kindergarten. The subject area is mathematics. This lesson plan focuses on subtraction using a balance. The students are first asked to demonstrate how a balance works using their bodies. The teacher asks for a volunteer and places a container in each of the child's hands. The teacher then asks the child to imagine what it would look like if the container on the right was heavy and left was light. The teacher would then have the rest of the class imagine what this would look like and use their bodies to show what it may look like. Then the teacher will show how a pan balance works. The teacher then puts eight pasta shapes on the left side and two on the right. The children then need to figure out how many shapes need to be moved to balance the scale. The teacher then gives each child a number cube and assigns them to the left or right side of the scale. The children then work out the subtraction equation and then place their pasta shapes on the scale. The teacher has the children record the differences and repeat until the scale balances. Next the teacher gives the students a paper bag and asks the children to place five or less on the left side of the scale and the same with the right side. Tell the other students to take away the pasta shapes until the scale balances. Have the students repeat this switching roles several times. Once finished, ask the children to record one of the ways they balanced the scale, in words or pictures.


Standards

Common Core State Standards – Mathematics

-Kindergarten, Counting & Cardinality

• CCSS.Math.Content.K.CC.A.3
  Write numbers from 0 to 20. Represent a number of objects with a written numeral 0-20 (with 0 representing a count of no objects).

-Kindergarten, Algebraic Thinking

• CCSS.Math.Content.K.OA.A.1
  Represent addition and subtraction with objects, fingers, mental images, drawings1, sounds (e.g., claps), acting out situations, verbal explanations, expressions, or equations.

-Kindergarten, Algebraic Thinking

• 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.

-Kindergarten, Algebraic Thinking

• CCSS.Math.Content.K.OA.A.5
  Fluently add and subtract within 5.

The lesson addresses standard CCSS.Math.Content.K.CC.A.3 by using pasta shapes to represent numbers 1-10.The lesson addresses CCSS.Math.Content.K.OA.A.1 and CCSS.Math.Content.K.OA.A.2 by using a pan balance to represent subtraction equations. As children take away pasta shapes they are performing a subtraction equation. The lesson addresses CCSS.Math.Content.K.OA.A.5 when the children are given time to make several combinations of subtraction numbers. The children add and subtract the pasta shapes to balance the scale.

Implementing this lesson would depend on how many pan balances are available to the teacher. If there are only two or three balances, this would probably be limited to six or less children at a time simply to avoid sharing issues. I would most likely do this at a individual center option. However, for the most part, I think this lesson could be successful. I think the main problem with this activity is that everyone would want to do it and there would only be a limited amount of materials. I think most children would not have a problem understanding this activity. I would even try doing more then ten pasta shapes, seeing if the children can subtract using 20 or less.

http://illuminations.nctm.org/Lesson.aspx?id=686