Mathematical Problem Solving by Flexible Resilient

MathematiciansPresented by Tracy Ortiz, Jamie Reichelt, and Jenna Stenclik

Addition and Subtraction Strategies in First Grade

How to Become a More Efficient Mathematician

11stst Grade Expectations Grade Expectations Master a number of different addition/subtraction strategies.

Choose the strategies that work best for him/her and for the particular problem.

Be flexible with strategies and choose ones that are efficient.

Check work with another strategy.

Full ModelFull Model

Counting objects, counting on fingers, drawing a picture

Show your work by Drawing all for addition

Taking away objects, taking away fingers, crossing off in a picture

Show your work by Drawing all and crossing off for subtraction

Prompt: How can you use a picture to solve this problem?

Prompt: How can you use a number line Prompt: How can you use a number line

and/or counting to solve this problem?and/or counting to solve this problem?

3 + 8 = ___

8 – 2 = ___

Counting On/Counting Counting On/Counting BackBack

Adding and subtracting are like counting up and back

Start with the larger number and count on or back (“hop”/”jump” forward or back)

Efficient strategy for solving single-digit addition and subtraction problems

Show your work with a number line or drawing a picture of the number in your head and dots

Using Facts We Know (Fluency)Using Facts We Know (Fluency)

Combinations of 10

6 + 3 + 4 = ____ I know 6 + 4 = 10 and 10 + 3 = 13

Doubles and Near Doubles

8 + 7 = _____ I know 7 + 7 = 14, so one more is 15

Fact Families – using what we know about addition to help with subtraction

10 – 7 = ____ I know 7 + 3 = 10, so 10 – 7 = 3

Fluency is so important because it is the foundation to solve more difficult problems.

Show your work with words and equations.

PromptPrompt: How can you break a number : How can you break a number

into helpful parts to solve this problem?into helpful parts to solve this problem?

9 + 7 = ___

Keep One/Break OneKeep One/Break One Importance of flexibility with numbers, knowing how to break numbers

apart in multiple ways.

Show your work with number bonds and/or equations.

Break one number into two parts so that you can make a landmark number

(e.g., 10 or a multiple of 10)

9 + 7 = ____

18 – 9 = ____

36 + 8 = ____

PromptPrompt: How can you use what you : How can you use what you

know about 10s and 1s to solve this know about 10s and 1s to solve this

problem?problem?

36 + 22 = ___

Using Place ValueUsing Place Value

Base 10 Model: Using or drawing base 10 blocks

Expanded Form: Breaking numbers into 10s &1s

30 + 6

20 + 2

50 + 8 = 58

Keep One/Break One: Adding multiples of 10 first

36 + 20 = 56 56 + 2 = 58

Show your work with base 10 drawings and/or equations

36 + 22 = ____

1st Grade Word Problem Comprehension

Do NowDo NowSolve the Following Problem: Solve the Following Problem:

John has 8 books. He has a green basket and a blue basket. How many books can he put in each basket?

Solve the Problem by Answering the Following:

Draw a picture to show what is happening in the problem

Write an equation to represent what is happening in the story.

What kind of problem is this?

How Did You How Did You Solve this Problem? Solve this Problem?

What did you envision?

What did you draw?

How did you solve this word problem?

What type of word problem is this?

What is Word Problem What is Word Problem Comprehension?Comprehension?

Think about the word problem like a story

You are a math detective, use the clues to help you solve the problem

Complete the Word Problem Complete the Word Problem &&

Think About the Following: Think About the Following:

Word Problem TypesWord Problem Types

How to Help Your ChildHow to Help Your Child Help them envision by having them sketch

Use prompts to help them think about the word problem like a story

Encourage them to THINK about the problem, before they attempt to solve it

Have your child explain WHY they solved the problem they did