standard_description: Understand subtraction as an unknown-addend problem. For example, subtract 10 – 8 by finding the number that makes 10 when added to 8.
problem_activity: Narrative
The purpose of this How Many Do You See is for students to subitize or use grouping strategies to describe the images they see.
When students notice that dots are being added on with each image, they look for and make use of structure (MP7).
Launch
Groups of 2
“How many do you see? How do you see them?”
Flash image.
30 seconds: quiet think time
Activity
Display image.
“Discuss your thinking with your partner.”
1 minute: partner discussion
Record responses.
Repeat for each image.
Student Facing
How many do you see?
How do you see them?
[IMG]
[IMG]
[IMG]
[IMG]
Student Response
Teachers with a valid work email address can
click here to register or sign in
for free access to Student Response.
Activity Synthesis
Display the first and third images.
“What changed from the first group of dots to the third group of dots.” (2 more dots were added.)
“The third group has 4 dots and 2 more dots. We can write that as ‘4 and 2’ or ‘
\(4 + 2\)
’.”


aligns: no