Standard(s):
[MA2019] (1) 1 : 1. Use addition and subtraction to solve word problems within 20 by using concrete objects, drawings, and equations with a symbol for the unknown number to represent the problem.
a. Add to with change unknown to solve word problems within 20.
b. Take from with change unknown to solve word problems within 20.
c. Put together/take apart with addend unknown to solve word problems within 20.
d. Compare quantities, with difference unknown, bigger unknown, and smaller unknown while solving word problems within 20.
[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