Video Transcript
A classroom has 35 students. If 13 of them are boys, how many
girls are there?
We know the whole amount or the
total amount of students is 35. We also know that 13 students are
boys. We don’t know how many students are
girls. If we subtract the number of boys,
which is 13, from the total, which is 35, that will tell us how many girls there
are. Let’s start by subtracting in the
ones column. Five ones take away three ones is
two. Five take away three is two. And in the tens column, we have
three 10s and we need to take away one. Three take away one is also
two. So, if a classroom has 35 students
and 13 of them are boys, 22 are girls.
We solved the problem by
subtracting the number of boys from the total number of students, but we can check
our answer using addition. So, we need to add together the
number of boys, which is 13, and the number of girls, which is 22, and it should
total 35 because we know there are 35 students in the class. We know that three ones plus two
ones is five. And we know that one 10 plus two
10s is three 10s. 13 plus 22 is 35. If a classroom has 35 students and
13 of them are boys, we know that there are 22 girls.
