Grade 2 - Addition and Subtraction Unit
The Addition and Subtraction Unit involves understanding the processes of addition and subtraction in order to solve problems and answer questions such as—
- If we know all of the parts, how can we find the whole?
- If we know the whole and one of the parts, how can we find the missing part?
- How can you use place value to explain the strategies you used to solve this addition (subtraction) problem?
- Given an equation, can you create an addition or subtraction situation to match it? How can you prove your situation matches the equation?
- What addition or subtraction strategy did you use and why?
Math Concepts and Skills:
The student develops and uses strategies for whole number computations in order to solve addition and subtraction problems.
The student:
- adds up to four two-digit numbers and subtracts two-digit numbers using mental math, knowledge of place value and properties of operations.
- uses a variety of strategies to solve one-step and multi-step word problems involving addition and subtraction within 100.
- generates—and solves—problem situations for a given addition and subtraction equation with whole numbers within 100.
Summative Assessment Task
Students determine how many puzzle pieces are left to finish a puzzle.
Instructional Tasks/Formative Assessments
Given a number of boxes put in a truck, students determine how many more boxes need to be put in the truck.
Students find different combinations of coins that add up to 75 cents.
Students determine how many leaves are still on a tree after 36 leaves blow off the tree.
Students determine if there are enough apples for all the students in grade 2, after several dozen more apples are brought to the school.
Given various point totals for a beanbag toss game, students determine how Valeria and Ethan each reached their total score.
Students count the number of legs on three spiders and six ladybugs.
Students determine the number of miles driven by Uncle Ted, when the total number of miles driven is known.
Students determine how many stuffed dogs are in a stuffed animal collection.