In This Unit of Study…

Students will use concrete models and drawings to add and subtract two whole numbers within 1,000.  Students determine and explain whether equations involving addition and subtraction are true or false.  In addition, students will extend the development of algebraic thinking skills by determining the unknown whole number in addition or subtraction equations, with the unknown in any position.

B.E.S.T. Benchmarks:

• MA.2.NSO.2.1 Recall addition facts with sums to 20 and related subtraction facts with automaticity.
• MA.2.NSO.2.2 Identify the number that is ten more, ten less, one hundred more, and one hundred less than a given three-digit number.
• MA.2.NSO.2.4 Explore the addition of two whole numbers with sums up to 1,000. Explore the subtraction of a whole number from a whole number, each no larger than 1,000.

Overarching Key Concepts:

• Fluency: Solve subtraction facts using ‘make a ten’ to build fluency to 20
• Add within 1,000 using models, representations, and strategies
• Subtract within 1,000 using models, representations, and strategies