Mathematical Problem Solving by Flexible Resilient Mathematicians Presented by Tracy Ortiz, Jamie Reichelt, and Jenna Stenclik

Addition and Subtraction Strategies in First Grade How to Become a More Efficient Mathematician

1 st 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 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 and/or counting to solve this problem? = ___ 8 – 2 = ___

Counting On/Counting Back 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) Combinations of = ____ I know = 10 and = 13 Doubles and Near Doubles = _____ I know = 14, so one more is 15 Fact Families – using what we know about addition to help with subtraction 10 – 7 = ____ I know = 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.

Prompt : How can you break a number into helpful parts to solve this problem? = ___

Keep 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) = ____ 18 – 9 = ____ = ____

Prompt : How can you use what you know about 10s and 1s to solve this problem? = ___

Using Place Value Base 10 Model: Using or drawing base 10 blocks Expanded Form: Breaking numbers into 10s &1s = 58 Keep One/Break One: Adding multiples of 10 first = = 58 Show your work with base 10 drawings and/or equations = ____

1 st Grade Word Problem Comprehension

Do Now 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 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 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 & Think About the Following:

Word Problem Types

How 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