Math Games

Grade 2 - Number

Standard 2.N.9 - Compare subtraction equations to find the related fact with numbers up to 1000.

Included Skills:

Demonstrate an understanding of addition (limited to 1- and 2-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.
• using the commutative property of addition (the order in which numbers are added does not affect the sum).
• using the associative property of addition (grouping a set of numbers in different ways does not affect the sum).
• explaining that the order in which numbers are subtracted may affect the difference.
• Model addition and subtraction, using concrete materials or visual representations, and record the process symbolically.
• Create an addition or a subtraction number sentence and a story problem for a given solution.
• Solve a given problem involving a missing addend, and describe the strategy used.
• Solve a given problem involving a missing minuend or subtrahend, and describe the strategy used.
• Refine personal strategies to increase their efficiency.
• Match a number sentence to a given missing addend problem.
• Match a number sentence to a given missing subtrahend or minuend problem.
• Explain or demonstrate why 5 + 6 = 6 + 5.
• Add a given set of numbers, using the associative property of addition, and explain why the sum is the same; e.g., 2 + 5 + 3 + 8 = (2 + 3) + 5 + 8 or 5 + 3 + (8 + 2).
• Solve a given problem, using horizontal and vertical formats.
• Solve a given problem using the standard/traditional addition algorithm.
• Solve a given problem using the standard/traditional subtraction algorithm.