Math Games

Grade 2 - Number

Standard 2.N.9 - Practice subtracting half from a number. Recognize the similar numbers in subtracting half of a number.

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
• explaining that the order in which numbers are added 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 solution.
• Solve a problem involving a missing addend, and describe the strategy used.
• Solve a problem involving a missing minuend or subtrahend, and describe the strategy used.
• Match a number sentence to a missing addend problem.
• Match a number sentence to a missing subtrahend or minuend problem.
• Add a set of numbers in two different ways, and explain that the sum is the same (e.g., 2 + 5 + 3 + 8 = 2 + 3 + 5 + 8 or 5 + 3 + 8 + 2).