This category encompasses the Common Core standards 1.OA.1 - 1.OA.8 (or 1.OA.A.1 - 1.OA.D.8). You can find helpful guides that provide videos and activities to help you teach these math standards here! Feel free to click through and find what you need!
The first two standards (1.OA.1 & 1.OA.2) focus on representing and solving problems that involve addition and subtraction. Students can use objects, drawings, and basic equations to represent numbers or word problems to solve equations. The sum of the numbers are equal to or less than 20.
The next two standards (1.OA.3 & 1.OA.4) focus on properties of operations and how to use those properties as strategies in solving addition and subtraction equations. For instance, if you have 6 bunnies in one box, and 4 bunnies in another box, then you have 10 fluffy bunnies: (6 + 4 = 10). Similarly, if you flip the boxes around, so you have 4 bunnies, and then 6 bunnies, you still have 10 fluffy bunnies: (4 + 6 = 10). The answer remains the same, and you are happy because you have bunnies. Anyway, these standards also discuss subtraction as unknown-addend problems: (10 - 7 = ? What makes 7 a 10?... 3! Therefore, 10 - 7 = 3).
The next two standards (1.OA.5 & 1.OA.6) cover addition and subtraction within 20 and the various methods students can use to solve equations: counting on, making ten, decomposing a number leading to a ten, etc.
The last two standards (1.OA.7 & 1.OA.8) cover working with addition and subtraction equations. Students learn how to read an equals sign, determine whether addition or subtraction statements are true or false, and find the missing whole number in an equation. Fun!