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### Course: Class 3 > Unit 3

Lesson 4: Addition and subtraction word problems# Three digit addition word problems

Work through a word problems that involve 3-digit addition.

## Want to join the conversation?

- Why aluminum and paper(5 votes)
- why does it have to be aluminum(4 votes)
- why not glass or plastic?(2 votes)
- do you really think you should be using your learning time asking THESE questions??(2 votes)

- how do we estimate?(1 vote)
- By rounding to the nearest number.

example

818+123.818 rounds to 820.123 rounds to 120.820+120=940.(1 vote)

## Video transcript

- [Instructor] We're told, the table gives the amounts
of materials Aya recycled. So we have the different materials here, and then it gives the various amounts. How many kilograms of paper
and aluminum did Aya recycle? So pause this video and see
if you can figure this out. Okay, so we're thinking
about paper and aluminum, so paper is right over here. She recycled 277 kilograms of paper. And aluminum is right over here. She recycled 134 kilograms of aluminum. And so we want the
combination, or the sum, of paper and aluminum, so it's going to be 277 kilograms plus 134 kilograms. So we really need to figure
out what 277 plus 134 is, and in multiple videos, we have talked about how there's many different
ways of approaching this. We could say, well let's
just break up the 134. We could start at, actually let
me do this on a number line. That sometimes is a fun thing to do. So if we were to just say,
this is our number line, and we're going to start
at 277 right over there. So first, we could add
100, because we have 100 right over there, so let's do that. If we add 100, so plus
100, where does it get us? Well if we add 100 here, we get to 377. So 300, I'll just write, 77. And then we could add three 10s, or 30. So then we're going to add 30. So let's add 30, so plus 30. What does that get us? So this is interesting. If you add 30 to 370, you would get to 400, and then we have another seven there, so that gets us to 407. So then we get to 407. And once again, this is just one way to try to think about it. And then, last but not
least, we could add the four. So then you say, we're there right now, and then we add plus four,
and seven plus four is 11, so 407 plus four is 411. So how many kilograms of paper
and aluminum did Aya recycle? Would be 411 kilograms. Kilo, kilograms, and we're done.