MAFS.1.OA.1.2 Solve word problems that call for addition of three whole numbers whose sum is less than or equal to 20, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem.

Cognitive Complexity Level: 1-Recall

[divider] [/divider] Students are able to… 

  • Identify actions in the story and determine what the question is asking
  • Represent problems using pictures, words and numbers
  • Use a variety of strategies to group numbers together and find a total
  • Explain their strategy for solving

[divider] [/divider] Students are able to…because teachers:

  • Provide problems with unknown situations
  • Ensure instruction includes the CRA model
  • Facilitate classroom discussion of strategies
  • Make connections to 1.OA.1.3

 [divider] [/divider] Questions to ask students:

  • Ask:  When adding the numbers: 2, 5, 8, how would you group the numbers to find the total?
    • Sample answer that indicates understanding: I would group the 2 and 8 to make a ten.  Then I would add 10 and 5 more to make 15.
  • Ask: What strategy could you use to add the numbers: 3, 7, 3
    • Sample answer that indicates understanding: I could add 3 and 7 to make a ten.  Then I could add 10 and 3 more to make 13.  OR I could 3 and 3 because I know my doubles.  That would give me 6 and then add 7 more to make 13.

[divider] [/divider] Additional Resources:

Additional in depth content knowledge

Video: Khan Academy – Add 3 Numbers

https://www.khanacademy.org/math/early-math/cc-early-math-add-sub-20/cc-early-math-add-20/v/adding-3-numbers

Video: Khan Academy – Add 3 Numbers Practice

https://www.khanacademy.org/math/early-math/cc-early-math-add-sub-20/cc-early-math-add-20/e/adding-three-numbers

[divider] [/divider] Sample Formative Assessment Tasks:

[divider] [/divider] Resources/Tasks to Support Your Child at Home:

  • Task: Encourage your child to add the three numbers in different ways.  Then encourage them to reflect on why they ordered the numbers the way they did to add the three numbers.

 

 

  • Task: Make adding three numbers relevant, by having them add three different objects at your home, such as:
    • Add the total number of dimes, nickels and pennies in the coin jar.
    • Add the total number of red, green and purple skittles.