First Grade Operations and Algebraic Thinking Tasks

Add and subtract within 20. (1.OA.3 - 1.OA.4)



1.OA.3 Apply properties of operations as strategies to add and subtract.2 Examples: If 8 + 3 = 11 is known, then 3 + 8 = 11 is also known. (Commutative property of addition.) To add 2 + 6 + 4, the second two numbers can be added to make a ten, so 2 + 6 + 4 = 2 + 10 = 12. (Associative property of addition.) (Students need not use formal terms for these properties.)


Additional

Standards Assessed

Task

Student Form

1.OA.7


1.OA.7



1.OA.4 Understand subtraction as an unknown-addend problem. For example, subtract 10 – 8 by finding the number that makes 10 when added to 8. Add and subtract within 20.


Standard 1.OA.4 is assessed under 1.OA.1 when students solve Add To/Change Unknown and Put Together/Take Apart/Addend Unknown tasks.