This week we will learn about multiples and least common multiples.
Students can best help themselves this week by studying and memorizing their multiplication facts (well, half of them anyway. They already know about "half"). Multiples - when we pick a number, like 4, and we multiply but another whole number, like 1, we get a multiple of 4. In this case, 4 x 1 = 4. The answer, 4, is the multiple. Ex: 4 x 2 = 8. 8 is a multiple of 4. We will also mention that 2 and 4 are the factors of 8. Least Common Multiple (LCM) - This is the smallest multiple, common to both/all of the orginal numbers we are given that they have in common. Ex: If we want to find the LCM of 4 and 6, we do the following. Step 1: List the first few multiples of 4: 4, 8, 12, 16, 20, 24, 28, 32 Step 2: List the first few multiples of 6: 6, 12, 18, 24, 30, 36, 42 Step 3: Look at each list and find the smallest number they have in common. In this case, it is 12. Even though they also share 24 and several other multiples, 12 is the LEAST COMMON multiple they share, so that is their answer. Why is this important? Suppose you are throwing a Labor Day party and need hot dogs. Hot dogs come in packages of 10, buns come in packages of 8. You can find the total number of packages that you need to buy to have an equal number of hot dogs and buns. Hot dogs (packs of 10): 10, 20, 30, 40, 50, 60, 70, 80 Buns (packs of 8): 8, 16, 24, 32, 40, 48, 56, 64, 72, 80 In order to buy an equal amount of hot dogs and buns, you should buy 4 packages of hot dogs and 5 packages of buns. LCM practice: (Pick one or more) 1) KhanAcademy 2) IXL 3) Mathgames 4) Sheppardsoftware
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core 3Archives
February 2018
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