Find an unknown addend
In today's lesson, we will be finding an unknown addend when the sum is changed.
Click on the play button to start the video. If your teacher asks you to pause the video and look at the worksheet you should:
- Click "Close Video"
- Click "Next" to view the activity
Your video will re-appear on the next page, and will stay paused in the right place.
Lesson summary: Find an unknown addend
The next lesson in Extending calculation strategies and additive reasoning is "Introduction to same difference"