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: Problem 1
a.   Take 60 seconds to list as many multiples of 2 as you can.
b.   What do you notice about the values in that list? What do you wonder?
c.   Is 3,498 a multiple of 2? How do you know?
Problem 2
a.   Make a list of the first fifteen multiples of 3.
b.   Which of the numbers in your list are multiples of 6? What pattern do you see in where the multiples of 6 appear in the list?
c.   Which numbers in the list are multiples of 7? Can you predict when multiples of 7 will appear in the list of multiples of 3? Explain your reasoning.


aligns: no