Video Transcript
Word Problems: Taking From
In this video, we will learn how to solve
problems to find the number of objects that are left after objects are taken from a
group. Here’s a box of 10 doughnuts. If we take a doughnut from the box, how
many will be left? Nine. We could write this as a subtraction
sentence. We had 10 doughnuts at the start. We’ve taken one doughnut from the
box. And there are nine doughnuts left. If we take another doughnut from the box,
then the number we’ve taken is two and the number left is eight.
We had 10 doughnuts at the start. We’ve taken two from the box. There are eight left. If we take three doughnuts, then there
are seven left. If we eat four doughnuts, there will be
six left. If we eat five, we’ll have five doughnuts
left. If we take six doughnuts, there are four
left. If we take seven doughnuts, there are
three left. If we take eight, we’re left with
two. If we take nine, there will be one
left. And if we eat all of the doughnuts, there
will be none left over.
Taking doughnuts from the box is the same
as subtracting. When we take objects from a group, the
number that we have left goes down. And if we take all the objects from a
group, there’ll be none left. Let’s practice taking objects from a
group and counting how many are left.
A child had seven marbles in their
pocket, but four fell out. How many marbles are left?
This is a word problem. We know the child had seven marbles in
their pocket to start with, and we know that four of these marbles fell out. We have to work out how many marbles
are left. To work out how many marbles are left,
we need to take away the four marbles that fell out of the pocket from the seven we had to
start with.
We could model this word problem using
counters. We’ve got seven counters because the
child had seven marbles in their pocket. We know that four marbles fell out. So we need to take four counters away
from all seven. One, two, three, four. How many are left? Let’s count. One, two, three. If we take four from seven, we’re left
with three. If a child has seven marbles in their
pocket and four fall out, they will have three marbles left.
Matthew had four apples. He ate two of them. How many are left?
Let’s try and write our word problem as
a number sentence. We know that Matthew had four apples at
the start. We also know he ate two of them. To find out how many apples Matthew has
left, we need to take the two that he ate from the four he had to start with. This is a subtraction word problem. When we take objects from a group, it’s
the same as subtracting. What is four take away two? To find out, let’s take two counters
away from our group of four counters. One, two. How many are left? There are two counters left. If we take two from four, then we get
two. Four take away two is two. If Matthew has four apples and he eats
two, he will have two apples left.
There are four frogs in a lake, and
then three frogs jump away. How many are left?
In this problem, we begin with four
frogs in a lake. Three of the frogs jump away. How many frogs are left? We started with four frogs, but three
of them jumped away. So to find out how many frogs are left,
we need to take away three frogs from our four frogs. Four take away three leaves us with one
frog. If we take three from four, we get
one. If there are four frogs in a lake and
three frogs jump away, there will be one frog left.
What have we learned in this video? We’ve learned how to find the number of
objects left after objects are taken from a group. We’ve also learned that if we take
objects from a group, the number that we have left gets smaller.
