Kindergarten, Math, Week 31

Monday

• Game: Make Ten - Subtraction from Games for Math
• See Math, Week 25 for instructions

Tuesday

• Subtraction with Manipulatives
• I wrote an equation and K. used Unifix Cubes to solve it
• I wrote 2 equations in horizontal form and 3 in vertical form
• Then I had K. write 5 equations.
• I hadn't thought that this might be a problem, but never having dealt with subtraction before, she didn't really know how. For example, I had written 8 - 6 =. K. wrote for one of her equations, 6 - 8 =. I told her she would learn about that type of subtraction when she is older, but for now, the larger number needs to come first. That didn't solve the problem, so I took a stick of 6 cubes and asked K. how many she could take away. We went through all the possibilities: 6, 5, 4, 3, 2, 1, and 0. We did this twice and it seemed to solve the problem.

Wednesday

• Game: Make Ten - Subtraction

Thursday

• I introduced the fact family triangles. The benefit of using these is that they teach both addition and subtraction.
• I used poster board for my triangles. The base is 7-inches and they are 4-inches tall.
• Write one fact family on each triangle. The largest number is at the top, so that "going down the hill" you subtract, and across the bottom you add. See photo below.
• 0/0/0; 0/1/1; 0/2/2; . . . 0/10/10
• 1/1/2; 1/2/3; 1/3/4; . . . 1/9/10
• 2/2/4; 2/3/5; 2/4/6; . . . 2/8/10
• 3/3/6; 3/4/7; 3/5/8; . . . 3/7/10
• 4/4/8; 4/5/9; 4/6/10
• 5/5/10
• I introduced them by writing the four facts; example: 2 + 3 = 5; 3 + 2 = 5; 5 - 2 = 3; 5 - 3 = 2 (in vertical form)
• I had her use manipulatives to get the answers for the subtraction problems, if she needed to.
• We did this for about ten fact families, and she still wasn't catching on to the fact that the same 3 numbers were used in each equation.
• I had her go get three different colors of pencils and had her connect the numbers; example: blue pencil line connecting all the 2's; red pencil line connecting the 3's; green pencil line connecting the 5's.
• We did this four times and she seemed to be getting it, so for the rest of the triangles, I covered the sum, and she gave me the answer, then I covered the other numbers and she gave me the answers; example: (cover 5) "3 plus 2 equals"; (cover 2) "5 minus 3 equals"; (cover 3) "5 minus 2 equals"

Friday

• Game: Triangles
• With K. not looking, I put out 5 triangles, covering 1 number on each triangle. (See photo below) I used 1-1/2" squares of black construction paper to cover the numbers.
• K. points to one and tell what number is hidden.
• If I think she is right, I say, "I agree".
• If I think she is wrong, I say, "Challenge" and tell the number I think is there.
• If she is correct, she takes the square, if I am right, I take the square.
• After we have completed all the triangles, whoever has the most triangles wins.
• The prize was 1/8 cup of trail mix.