Solving Math Problems: Addition & Subtraction!

Solving Math Problems: Addition & Subtraction!

Grade 2 Mathematics Ontario Curriculum 45-minute lesson

Our Learning Goals Today

Solve addition and subtraction problems within 100 Use objects and drawings to show our thinking Explain our problem-solving steps clearly Have fun with math!

Success Criteria - How We Know We're Learning!

I can use objects and drawings to show addition and subtraction I can solve problems about real things in my world I can share my thinking with my classmates I can explain how I solved the problem

Materials We'll Use Today

Base-10 blocks (tens and ones) Whiteboards and markers Number lines Problem-solving worksheets Our thinking caps!

Warm-Up: Mental Math Sprint!

Look at the math problem on the board Solve it in your head Write your answer on your whiteboard Be ready to share your strategy!

Let's Solve a Problem Together!

Story Problem: There are 38 apples in the basket. The farmer picks 25 more apples. How many apples are there now? Let's use our base-10 blocks to solve this! We'll draw pictures too!

Modeling with Base-10 Blocks

Guided Practice Time!

Work with your partner Use base-10 blocks for each problem Draw pictures to show your thinking Explain your solution to your partner

Sharing Our Strategies

Who would like to share how they solved one of the problems? What strategy did you use? Did anyone solve it a different way?

Different Ways to Solve Problems

{"left":"Using base-10 blocks\nDrawing pictures\nUsing a number line","right":"Mental math strategies\nBreaking numbers apart\nCounting on or back"}

Independent Challenge

Maya had 47 stickers. She gave 19 to her friend. How many stickers does Maya have now? Solve this problem using your favorite strategy Show your work clearly Be ready to explain your thinking!

Great Job, Mathematicians!

Today we learned that there are many ways to solve addition and subtraction problems. The most important thing is to show our thinking clearly and help each other learn!