khan academy multiplying decimals using area models

#Khan academy multiplying decimals using area models plus#

Is 40, but we're not just saying five, we're saying five tens, so five tens times eight And 50 times eight? Well, five times eight

#Khan academy multiplying decimals using area models plus#

Is going to be 50 times eight, So it's going to be 50 times eight, plus six times eight. And then you could distribute the eight and you could say, look, this You could say that, look, 56, this is the same thing as 50, five tens, that's 50 plus six ones, so 50 plus six, and all Let's say that we wanted to figure out, let's say that we wanted to figure out, let me give ourselves some space, let's say that we wanted to figure out what 56 times eight is. To break up these numbers and how you could re-associate And the reason why I alsoīroke it up that way, this way, is that theĮxercises on Khan Academy make you do this to make sure that you really are understanding how To do this immediately in your head and that's all good, but it's good to understand

$khan academy multiplying decimals using area models$

And so the whole reason, some of y'all might have just been able So you can view this as a thousand 42's or maybe a little bit more intuitively you could view this as 42 thousands. Seven times six first, you're going to get 42, and you're gong to have 1,000 times 42. Times six first to get, and you know where there is going, so if you multiply the Seven first to get 7,000, or I could do the seven Notice, it's 1,000 times seven times six. The seven times six first we can put the parentheses around that, times seven, times six. So we could rewrite this as 1,000 times, and if we're going to do The seven times six first, before we multiply by the thousand. It sounds very fancy,īut it just says that, hey look, we can multiply Or you could do the seven times six first, and this is, this right over here is the associative Which would be 7,000, and then times six. And so you could view it as, you could do 1,000 times seven first,

So this is the same thing asġ,000 times seven times six. So 7,000 is the same thingĪs 1,000 times seven, or seven times 1,000. This will also help us with a little bit of practice of our

That we really understand what is going on here. So I'm going to have 42 thousands, three zeros there. Just cut to the chase like that, and another way to thinkĪbout it is like, look, six times seven is 42, and then since we're talking about thousands, we're not just talking about seven, we're talking about seven thousands. To cut to the chase and say, hey look, six times seven thousands is going to be 42 thousands. Thing, or 42 of that thing, and in this case we have 42 thousands. Six, I'm now going to have seven times six of that Have seven of anything, and here I have seven thousands, and I multiply that by So let's say that we wanted to calculate what 7,000 times six is. Start on the left side going right.įinally, place the decimal point in the answer between 7 and 4 this is three places to the left of the answer.- What I hope to do in this video is getĪ little more practice and intuition when we're In this example, there are three decimal places in the numbers used to multiply, so count three places in the answer. To place the decimal point, determine how many decimal places are in each factor. 5 (tenths) and 8.63 times 5 (ones).Īdd the products (answers to the multiplication). Now add the answers from the multiplication of 8.63 times. This time, place 43 below the line with the 4 next to the 3. Multiply 8 × 5 = 40 and add the 3 brought from the previous answer to make 43. Place the 1 at the bottom, to the left of the 5, and place 3 over the 8. Multiply 5 × 6 = 30 and add the 1 that was brought from the previous multiplication to makes 31. Place the 5 to the left of 0 and place the 1 over the 6. Now, start multiplying 3 by 5 in the ones place. We must now multiply the other 5 in the problem by all the numbers in the first row.īefore multiplying, place a zero below the first column on the right, under the 5, as a place-holder. This time, place 43 below the line with the 4 next to the 3 because there arenâ€™t any more columns to multiply. Multiply 8 × 5 = 40, plus the 3 brought from the previous answer, makes 43. This gives us 5 × 6 = 30, plus the 1 that was brought from the previous multiplication, for a total of 31. Multiply the 5 in the first column on the right with the 6. Place the 5 on the bottom right and place the 1 over the 6. Start by multiplying the numbers on the right 5 × 3 The number 8.63 has more digits than 5.5, so place 8.63 on top. Place the number with more digits on top.