standard_description: Recognize that in a multi-digit number, a digit in one place represents 10 times as much as it represents in the place to its right and 1/10 of what it represents in the place to its left.
problem_activity: Problem 1
For parts (a) and (b) below,
Solve. Show or explain your work.
Assess the reasonableness of your answer.
a.   910 × 233
b.   852 × 488
Problem 2
Damian’s work on a multiplication problem is shown below.
[IMG]
a.   Why is Damian’s answer not reasonable? Use estimation in your explanation.
b.   What mistake do you think Damian made? Why do you think he made that mistake?
c.   Find the correct product of 5,126 × 47.


aligns: no