standard_description: Add up to four two-digit numbers using strategies based on place value and properties of operations.
problem_activity: Problem 1
a.   Solve.
10
$$\times$$
23 = ___________
10
$$\times$$
450 = ___________
10
$$\times$$
10,870  = ___________
b.   What do you notice about Part (a)? What do you wonder?
c.   Use your conclusions from Part (b) to find the solutions below.
___________
$$\times$$
10 = 5,090
60,200
$$\div$$
10 = ___________
___________
$$\div$$
10 = 3,050
20,008
$$\times$$
___________ = 200,080
Problem 2
There are about 39,000 fourth graders in Mississippi and about 390,000 fourth graders in Texas. There are about 3,900,000 fourth graders in the United States.
a.   How many times more fourth graders are there in Texas than in Mississippi? How many times more fourth graders are there in the United States than in Texas?
b.   There are about 3,900 fourth graders in Boston, MA. How many times more fourth graders are there in the United States than in Boston?


aligns: no