Session 1 - Strategies to Add and Subtract within 20

Strategies to add and subtract within 20 - Grade 1

Step 1

Get Prepared (15 minutes):

Gather materials and review the lesson.
You will need copies of the following handouts. Make copies or turn on computers.

Note:

This Addition & Subtraction Presentation Slides is another way to present this toolkit to students. It includes the lessons that are in the toolkit. This is a way to go through and do the lessons together, and to see how the lessons can be separated a bit for young attention spans. There are “notes” at the bottom of the note section of the slides. These notes will direct the facilitator on how to guide the students, have prompts, and show answers.

Step 2

Think: Pre-Lesson Knowledge Check! (10 minutes)

Pre-Lesson Knowledge Check Task: Readiness Check!

Pre-lesson Knowledge Check Task:

Directions:

Readiness Check! is given to students with the facilitator in small groups or one-to-one.
It is encouraged to have the facilitator note strategies the students show during the assessment. (these strategies are noted for each question)
Students can write, say the number, or any verbal answer can be recorded for the student.
The ten-frames are the model provided; however, students may use any model to evaluate the ability to add and subtract.

Focus: MP 4: Model with mathematics and MP 7: Look for and make use of the structure

Decorative question mark:

Why are students doing this/what are they getting out of it?

This assessment is understanding the student's ability to recognize numbers, groups of numbers, and simple addition to 10. Students are encouraged to use a ten-frame model to demonstrate thinking. This is not testing memorization.

Directions for Scoring & Understanding Student Responses

While students are doing the pre-knowledge check, the facilitator will want to listen and observe strategies and knowledge the student knows such as did the student count, use fingers to count, or need an explanation of the addition and subtraction symbols. When they feel ready to share, look at their answers/responses. Use the suggestions below to help decide if they “got it” or are still struggling with this skill.

Sample Thinking Prompts:

Common Problems	Question to Pose to Student
Student can't identify or name a single number on the ten-frame (cardinality).	Can you show me ____ items? Can you put those in groups of 10? Show me on the ten-frame ____ number of objects.
Student can’t add two single digits with numbers 0-5 accurately with a ten-frame.	Can you show me your two groups of numbers? How many do you have if you put them together or combine them?
The student writes division sentences but does not know how to solve.	Is there a way to draw this out so you can understand how it is being equally shared?
Student can’t count on a number.	With your fingers, can you show me 5? Now add or show me two more fingers. 7 fingers are shown. How many fingers do you have showing?

Please Note

The intention is not to grade this activity but to use it to gauge what knowledge the student brings with them to the toolkit lesson.

If this activity seems to take a long time, this would be a good breaking point.