### Video Transcript

Ethan bought five blue pens and
two green pens. How many pens does he have in
total? Find the matching number
sentence. Three plus five equals eight,
five plus two equals seven, five plus two equals six, or five plus four equals
nine.

Let’s take our time and read
through this word problem again. Ethan bought five blue pens and
two green pens. Let’s underline these two
amounts; they’re going to come in useful later on. The question continues, how
many pens does he have in total? And we know, of course, that
that word “total” means that we’re going to have to add to find the answer. We need to find how many pens
Ethan has altogether. This is an addition word
problem. We’re putting two groups of
objects together. Let’s model the problem. We could use a part–whole model
using counters. Five blue counters to represent
Ethan’s five blue pens. And we can use two green
counters to represent his two green pens.

And the question is asking us,
how many counters are we going to need to put in this top circle of our
part–whole model? In other words, how many pens
did Ethan have in total? Let’s move our counters one by
one into that top circle. And we’ll count them as we
do. Altogether, Ethan is going to
have one, two, three, four, five, six, seven pens. We solved the word problem by
modeling it using counters. Five blue pens plus another two
green pens makes seven pens in total. We can also show our word
problem as a number sentence.

And in the second part of the
question, we’re asked to find the matching number sentence. Which number sentence shows us
that five blue pens and two green pens makes a total of seven pens? Well, it’s this one here, isn’t
it? Ethan has seven pens in
total. And the matching number
sentence is five plus two equals seven.