Adding Three Numbers
In this video, we will learn how to
add three one-digit numbers in any order using different strategies.
When were adding three one-digit
numbers, we can add them together in any order. We could add in the order that the
numbers are given. If we add four and three, we get
seven. Then, we just need to add the two
to the seven. Four plus three is seven, and two
more makes nine. Or we could add together the three
and the two first. Three plus two is five. Then, we can add our third number;
four plus five gives us the same total of nine. We could change the order of the
numbers round again and add four and two and three. Four and two is six. Six and three is nine.
Sometimes, when were adding three
numbers together, we can find pairs of numbers that make 10. For example, if were adding six and
three and seven, first, we could make 10 by adding three and seven. Three plus seven makes 10, and six
more makes 16. First, we make 10 by adding seven
and three. Then, we add the third number, six,
to 10. 10 plus six is 16.
Sometimes, we can use other number
facts to help us add three numbers. We can use our knowledge of doubles
to help. We could add together three and one
to make four. And we can double four to find the
answer. Double four or four plus four is
eight. Three plus four plus one is
eight. Let's practice adding three
one-digit numbers in any order using the strategies weve learned, doubling and
making bonds to 10.
Hannah has 20 counters. Use the counters to find the
missing number: 11 plus what plus five equals 11 plus nine.
In this question, we have to find
the missing number. Hannah is adding three numbers
together: 11, the missing number, and five. And the question tells us to use
the counters to help us find the missing number. Hannah has 11 blue counters. She has five pink counters. And she has four green
counters. The missing number is four. 11 plus four plus five is equal to
11 plus nine. Four plus five equals nine. 11 plus nine is 20. 11 plus four plus five is 20. The missing number is four.
Three plus five plus one equals
When were adding three numbers
together, we can add them in any order. Lets start by adding together five
and one. One more than five is six. Weve added our five and our
one. Now, all we need to add is the
three. Six and three is nine. If we start at five and add one
more, we have a total of six. Then, all we have to do is add the
three to six. Three more than six is nine.
We could also start at three, add
five to take us to eight. Eight add one is nine. It doesnt matter which way we add
the numbers; the total is nine.
Complete the following: one plus
five plus four equals what.
In this question, we have to add
together three one-digit numbers. We could start with the largest
number, number five, and add four more to make nine. Five, six, seven, eight, nine. Four more than five is nine. Then, we could add the one to make
10. Five plus four is nine. Nine plus one is 10.
Another way we could add these
three numbers together is to add together the four and the one first to make
five. Then, we could use our knowledge of
doubles to add together five and five. We know that double five is 10. We already have one five. And if we add together four plus
one, we have another five. Double five is 10. The missing number is 10.
What have we learned in this
video? Weve learned that when we add three
numbers, we can add in any order. And the total stays the same. We used strategies like making 10
to help us add three numbers or doubles facts to help us add three numbers.