Warm-up Which One Doesn’t Belong: Numbers with 0, 2, and 5
Which one doesn’t belong?
Activity 1 What If There is Nothing to Decompose?
Here are some numbers you saw earlier. Each number has at least one 0. From each number, 1,436 is being subtracted.
Make sense of the problems and explain to a partner.
Use the approach in the first problem to find these two differences:
Find the value of each difference. Be prepared to explain your reasoning. If you get stuck, try subtracting using the expanded form.
Activity 2 What is Your Age?
Jada recorded the birth year of some of her maternal grandparents for a family history project.
As of this year, what is the age of each family member? Show your reasoning. Use the standard algorithm at least once.
Here is how Han found
How can you tell by estimating that Han has made an error?
What error did Han make?
Find the value of