Grade 2 - Number
Standard 2.N.9 - Practice solving addition sentences up to 100.
Included Skills: Addition
Demonstrate an understanding of addition (limited to one- and two-digit numerals) with answers to 100 and the corresponding subtraction by: • using personal strategies for adding and subtracting with and without the support of manipulatives • creating and solving problems that involve addition and subtraction • explaining that the order in which numbers are added does not affect the sum (commutative property) • explaining that the order in which numbers are subtracted may affect the difference. • Achievement Indicators: - 2N9.1 Model addition and subtraction, using concrete materials or visual representations, and record the process symbolically. - 2N9.2 Solve a given problem, using horizontal and vertical forms. - 2N9.3 Add a given set of numbers in two different ways, and explain why the sum is the same; e.g., 2 + 5 + 3 + 8 = (2 + 3) + 5 + 8 or 5 + 3 + (8 + 2). - 2N9.4 Create an addition or a subtraction number sentence and a story problem for a given solution. - 2N9.5 Solve a given problem involving a missing addend, and describe the strategy used. - 2N9.6 Match a number sentence to a given missing addend problem. - 2N9.7 Solve a given problem involving a missing minuend or subtrahend, and describe the strategy used. - 2N9.8 Match a number sentence to a given missing subtrahend or minuend problem. - 2N9.9 Refine personal strategies to increase their efficiency.