1.OA.D.7 - Understand the meaning of the equal sign, and determine if equations involving addition and subtraction are true or false. For example, which of the following equations are true and which are false? 6 = 6, 7 = 8 - 1, 5 + 2 = 2 + 5, 4 + 1 = 5 + 2.

1.NBT.A.1 - Count to 120, starting at any number less than 120. In this range, read and write numerals and represent a number of objects with a written numeral.

2.OA.A.1 - Use addition and subtraction within 100 to solve one- and two-step word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem. (See Glossary, Table 1.)

2.NBT.B.5 - Fluently add and subtract within 100 using strategies based on place
value, properties of operations, and/or the relationship between
addition and subtraction.