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Bellringer. Do problems 1 – 6 on your study guide Be prepared to share your answers. Bell-Ringer:. Find the least common multiple 1) 4 and 12 2) 8 and 3 3) 12 and 11 4) 4 and 7 5) 8 and 10 6) 15 and 40. Bell-Ringer:. Find the least common multiple 1) 4 and 12 12 2) 8 and 3 24
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Bellringer • Do problems 1 – 6 on your study guide • Be prepared to share your answers
Bell-Ringer: • Find the least common multiple • 1) 4 and 12 2) 8 and 3 • 3) 12 and 11 4) 4 and 7 • 5) 8 and 10 6) 15 and 40
Bell-Ringer: • Find the least common multiple • 1) 4 and 12 12 2) 8 and 3 24 • 3) 12 and 11 132 4) 4 and 7 28 • 5) 8 and 10 40 6) 15 and 40 120
Learning Objective: • I will use the least common multiple to add and subtract fractions.
Steps for Common denominators adding and subtracting fractions • 1. Add/subtract numerator ONLY and bring denominator straight over. • 2.Simplify
Adding Fractions with different denominators Problem: You can’t add fractions with different denominators without getting them ready first. They will be ready to add when they have common denominators Solution: Turn fractions into equivalent fractions with a common denominator that is find the Lowest Common Multiple (LCM) of the two denominators
Steps for Common denominators adding and subtracting fractions • 1. Find the LCM of both denominators to find a common denominator. • 2. Multiply the numerator and the denominator by the same number to make the denominator the LCM • 3. Add/subtract numerator ONLY and bring denominator straight over. • 4.Simplify
Finding the Lowest Common Denominator • The least common multiple of two numbers is the lowest number in BOTH lists of multiples Multiples of 2 are 2, 4, 6, 8, 10…… Multiples of 3 are 3, 6, 9, 12, ……… What is the lowest common multiple?
Finding the Lowest Common Denominator • The lowest common multiple of two numbers is the lowest number they will BOTH divide into 2 divides into 2, 4, 6, 8….. 3 divides into 3, 6, 9…. What is the lowest number 2 and 3 both divide into?
You can’t add fractions with different denominators + The Lowest Common Multiple of 2 and 3 is 6 so turn all fractions into sixths Special form of 1
Lowest common denominator is 10 so make all fractions tenths
Finally the fractions are READY to add. I just have to add the numerators 9+14=23 It is 3/3 So I multiply 3/7 by 3/3 It is 7/7 So I multiply 2/3 by 7/7 What is the lowest number BOTH 3 and 7 divide into? Hmmmmm?????? What special form of 1 will change 7 to 21. Hmmmm? What special form of 1 will change 3 to 21. Hmmmm? It is 21. So that is my common denominator Now 3x3=9 and 2x7=14 Now I know the new numerators
Adding Mixed Numbers • Separate the fraction and the whole number sections, add them separately and recombine at the end
LET’S TRY 3 2 4 5 • - • - • + 7 5 12 8 5 7 10 6 8 1 9 2
PROBLEM HUNT • Working with a partner, stand at the problem you are assigned • Write down the solution to your problem on your graphic organizer • Look around the room for that solution on a sticky note to show what question you need to move to • Both partners need to have the answers down and SHOW THEIR WORK!
DOL: 4 1 5 2 • + • - • - • + 5 1 6 2 4 1 5 3 9 1 10 2
DOL: 4 1 13 5 2 10 • + • - • - • + 1 5 1 2 3 6 2 6 4 1 7 5 3 15 9 1 14 7 10 2 10 5