Grade 2 Unit 2
Using Addition and Subtraction Strategies to Solve Story Problems
Unit 2 Overview:
In unit 2, students will extend their understanding of addition and subtraction of one and two-step word problems. They will use addition and subtraction strategies based on place value within 100. Try to practice addition/subtraction strategies with your child. Focus on add/subtract 0, 1, 2, 10, ways to break apart 10, and doubles.
- Students will use addition and subtraction counting strategies (plus/minus 0, 1, 2 and make/break apart 10, and doubles/halving) working towards fluency within 20. (2.OA.B.2)
- Students will develop an understanding of even and odd numbers (within 20) by using concrete materials. (2.OA.C.3)
- Students will use various models based on place value and properties of operations to show the relationship of adding and subtracting within 100. (2.NBT.B.5) Note: Possible strategies to use as appropriate for students include: base-ten concrete models, base-ten quick pictures, breaking apart, number lines, compensation, hundreds chart
- Students will use different models to solve real world addition and subtraction story problems using structures with all subtypes involving one-step with sums and differences within 100. (2.OA.A.1)
Home Activities
- Discuss situations in your every day world where you need to add or subtract. Create real life problems using adding and subtracting within 100 with your child.
- Ask your child to share with you one of the strategies he/she has learned to solve the problem.
- Have fun exploring even and odd numbers. Create a two digit number up to 20 and have your child count out that number of objects. Split the amount into two teams to see if both are the same number. Discuss how if each team has the same, the number is even. If one team has 1 more, than it is an odd number.
Activities
Websites/Games
Build Expressions Equal to One Hundred (Dreambox Website)- Click the “Build Expressions Equal to One Hundred” under second grade number sense. Students will use snap blocks to develop strategies to determine if the expressions are equivalent, up to one hundred. (2.NBT.B.5)
Addition with Tens on the Number Line- (Dreambox Website) Click “Addition with Tens on the Number Line” under Second Grade Addition and Subtraction. Using an open number line, students jump by tens to decompose addition problems into friendly steps. (2.NBT.B.5)
Matching Number Pairs for One Hundred- (Dreambox Website) Click “Matching Number Pairs for One Hundred” under First Grade Addition and Subtraction. Students practice computation strategies and identify number patterns and relationships to make one hundred in a variety of ways. (2.NBT.B.5)
Breakapart- Great game to practice breaking down numbers to efficiently add and subtract
Missing Numbers- Great games to practice missing numbers in addition and subtraction problems.
Other Resources
Math Slide Addition - (Ipad App) This is a multiplayer game helping students understand tens & ones; numbers up to 100.
Thinking Blocks: Addition - Thinking Blocks Addition teaches children how to model and solve word problems involving addition and subtraction.
Number Pieces - Number Pieces helps students develop a deeper understanding of place value while building their computation skills with multi-digit numbers.
Math Words
These are vocabulary words that students will be exposed to throughout the unit.
add
addend
break apart ten
difference
doubles
efficient
equal
equal groups
equation
even
hundreds chart
fluent
halving
make ten
mental math
model
open number line
odd
part-part-whole model
structures
subtract
sum
total
ten frame