Standard(s):
[MA2019] (1) 2 : 2. Solve word problems that call for addition of three whole numbers whose sum is less than or equal to 20 by using concrete objects, drawings, or equations with a symbol for the unknown number to represent the problem.
[MA2019] (1) 6 : 6. Add and subtract within 20.
a. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by counting on.
b. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by making ten.
c. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by decomposing a number leading to a ten.
Example: 13 - 4 = 13 - 3 - 1 = 10 - 1 = 9
d. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by using the relationship between addition and subtraction.
Example: Knowing that 8 + 4 = 12, one knows 12 - 8 = 4.
e. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by creating equivalent but easier or known sums.
Example: adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13
[MA2019] (1) 21 : 21. Build and draw shapes which have defining attributes.
a. Distinguish between defining attributes and non-defining attributes.
Examples: Triangles are closed and three- sided, which are defining attributes; color, orientation, and overall size are non-defining attributes.
