About this video
Sal shows how to write 'divide 18 boxes into two equal stacks' as a division expression in three ways: as a fraction 18/2, with the division sign 18 ÷ 2, and with the long-division bracket. He then draws 18 boxes, splits them into two equal groups and finds 9 in each, so 18 ÷ 2 = 9.
You'll be able to
- write a division expression in three different ways.
- explain that 18 ÷ 2 means splitting 18 into 2 equal groups.
- find the value of a simple division expression by making equal groups.
Key words
- division
- Splitting a number of things into equal groups.
- expression
- A maths phrase made of numbers and operation signs, like 18 ÷ 2.
- equal groups
- Groups that each have exactly the same number of things.
Transcript
What expression can be used to show dividing 18 boxes into two equals stacks? Find the expression three times using different ways to write division. Find the value of the expression. So let's just do this top part right here. We have 18 boxes, and we want to divide them into two equals stacks, so we want to divide 18 by 2.
And the way we would write this, and we'll think a little bit more about what this means, we could write this as 18 over 2. This means 18 divided by 2. We could write it as 18 divided by 2, just like that, or we could write it as 18 divided by 2. Now before we evaluate it, they say find the value of the expression.
Let's think about what this means. We have 18 boxes and we want to divide them into two equal stacks. Let me draw 18 boxes. So I have 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12-- almost there-- 13, 14, 15, 16, 17, 18. So those are my 18 boxes, and I divide them into two equals stacks or two equal groups.
So if I want to divide these into two different groups that have the same number of boxes, I could just eyeball it, and say, well, let's make these top ones one group. Let's make that one of the groups, and let's making these bottom ones another group. And these are equal groups.
How many do we have in each group? Well, in the top one, we have one, two, three, four, five, six, seven, eight, nine, and in the bottom one we have one, two, three, four, five, six, seven, eight, nine. So we've split it into two groups of nine. So 18 divided into two equal groups is equal to 9, or 18 divided by 2 is equal to 9, or 2 goes into 18 nine times.
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