Grade 4 Math 5 4 What are Common Multiples New version

great for math number 49 this is lesson 5.4 and it's remake it's new version of what are common multiples we have 3 times 4 those are factors of 12 12 is the product it's multiple of both three or four multiple is product and the multiples of two are two four six eight ten twelve and we could keep going we could keep skip counting by two there would all be multiples of two and the multiples of three are three six nine twelve fifteen and we could keep going skip counting by three and the multiples of four are four eight twelve sixteen and we could keep going skip counting by four and by looking at these list of multiples we can see the multiples that each list has in common so if we looked at these lists do you see any numbers they have in common well the multiples of two and the multiples of 3 both have 6 and they both have 12 don't they and the multiples of 3 and the multiples of 4 have 12 in common those are common multiples and they both have 24 in common don't they see we can find their common multiples by making list of their multiples so take look at this calendar on this calendar this is the work days that emma works in the days that tala works now emma works every three days and tala works every five days so emma works on the third the sixth the ninth the twelfth see it's every three days see she works and then one two three she works again one two three she works again but tyler works every fifth day so she goes one two three four five now she works and then one two three four five and now she works and we can see the common multiples the common days that they work they're both going to work on the 15th and they're both going to work on the 30th together see that we can see the days that they work together the days they work together are common multiples of three and five if we make list of the multiples of three and list of the multiples of five they have 15 and 30 in common the common multiples are shared multiples all right so it's like shared products okay the multiples of two and eight we list all the multiples of two we start with 2 times 1 is 2 2 times 2 is 4 2 times 3 is 6. see it's two times counting number so we list all the multiples of two we do the same thing for eight eight times one is eight eight times two is sixteen eight times 3 is 24 and we keep going skip counting by eight and we can figure out and circle the common multiples they have they both have an eight they both have 16 they both have 24 and we could keep going up and skip counting by two here and skip counting by eight here and there would be even more they have in common usually the most important one is the smallest one they have in common the least number that's the important number okay for the multiples of three and four what are their common multiples they have 12 24 and 36 in common we made all the list of multiples for three three times one three times two three times three three times four see we did the same thing for the fours four times one four times one four times two four times three and we kept going and we circled the ones they have in common twelve twenty four and thirty six look at the common multiples for seven and eight look at this there's nothing and then all of sudden it's 56 and you want to know something that's what seven times eight is it's 56. sometimes we can find common multiple by multiplying the two numbers together so let's figure this out we want to know if they're factors or multiples of 30 is it factor or multiple of 30 well factor is number that can be multiplied by another number to find product multiple is product so if it's the answer then it's the multiple okay 30 is the answer in 30 times 1 so it's multiple but look it's also number that's multiplied to get it 30 times 1 is 30 so it's both factor and multiple five well five times six is thirty so that's factor it's number we multiply together to get thirty sixty that's the answer so that's multiple ten it's number we multiply together to get to 30 so that's factor six that's number we multiply together with another number to to get 30. so that's factor and 90 we have to multiply something to get 90 30 times counting number so it's multiple it's an answer see so if it's product then it's multiple if it's one of the multiplicands or or the factors are going to be inside the problem here they're what's multiplied together okay so want to thank and give shout out to dr ahmad because he found mistake in my old version video and like to remake them when there's mistake so appreciate when people find an error put it on list for remake and remake them to make them better okay so thank you for catching that error had one of my multiples wrong my multiplication facts were wrong and i'm human and make mistakes so appreciate the good sharp eyes that keep me on my toes we're going to talk about prime numbers next and hope i'll see you there bye