standard_description: Add and subtract within 1000, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method. Understand that in adding or subtracting three-digit numbers, one adds or subtracts hundreds and hundreds, tens and tens, ones and ones; and sometimes it is necessary to compose or decompose tens or hundreds.
problem_activity: Problem 1
a.   Look at the number line below:
[IMG]
Based on where 0 and 100 are, what number do you think the question mark is on? Explain your choice.
b.   Look at the number line below:
[IMG]
Based on where 0 and 1,000 are, what number do you think the question mark is on? Explain your choice.
Problem 2
a.   What is the location of the following point?
[IMG]
b.   What is the location of the following point?
[IMG]
Problem 3
a.   Plot 27,361 on a number line from 27,360 to 27,370.
b.   Plot 27,361 on a number line from 27,300 to 27,400.
c.   Plot 27,361 on a number line from 27,000 to 28,000.
d.   Plot 27,361 on a number line from 20,000 to 30,000.


aligns: no