standard_description: Mentally add 10 or 100 to a given number 100–900, and mentally subtract 10 or 100 from a given number 100–900.
problem_activity: Problem 1
Three different students solved the problem
$$ 232 \div 8$$
. Your teacher will assign you one of the strategies below. Explain what the student did and whether the strategy they used works. Be prepared to share your thinking.
| Student A            |https://d21royfkw9g4l6.cloudfront.net/ZoPLED891zSmYOWqanUdIv_ZMZYXA.png|  |https://d21royfkw9g4l6.cloudfront.net/ZoPLED891zSmYOWqanUdIv_ZMZYXA.png| image:: https://d21royfkw9g4l6.cloudfront.net/ZoPLED891zSmYOWqanUdIv_ZMZYXA.png |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Student B            |https://d21royfkw9g4l6.cloudfront.net/GjKY5qmrEGOwHjEfJMqaOe_IY0IDR.png|  |https://d21royfkw9g4l6.cloudfront.net/GjKY5qmrEGOwHjEfJMqaOe_IY0IDR.png| image:: https://d21royfkw9g4l6.cloudfront.net/GjKY5qmrEGOwHjEfJMqaOe_IY0IDR.png |
| Student C            |https://d21royfkw9g4l6.cloudfront.net/cu4zJFEkmogo8n93orpF2r_KS83E1.png|  |https://d21royfkw9g4l6.cloudfront.net/cu4zJFEkmogo8n93orpF2r_KS83E1.png| image:: https://d21royfkw9g4l6.cloudfront.net/cu4zJFEkmogo8n93orpF2r_KS83E1.png |
Problem 2
Solve.
| $$40\div4$$                        $$80\div4$$                        $$83\div4$$ | $$50\div5$$                        $$150\div5$$                        $$10\div5$$                        $$140\div5$$ | $$30\div3$$                        $$21\div3$$                        $$51\div3$$ |
|-----------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------|


aligns: no