Grade C LCM and HCF Understand find LCMs

Grade C LCM and HCF Understand find LCMs and HCFs If you have any questions regarding these resources or come across any errors, please contact helpful-report@pixl. org. uk

Key Vocabulary Factor Multiple

How to find the HCF • There are different methods you can use to find the HCF and LCM of a pair of numbers. • We will first look at the ‘listing’ method which works well for smaller numbers • Following this, the use of Venn Diagrams will be explored. .

How to find the LCM ‘Listing method’ By ‘Lowest Common Multiple’ we mean the lowest multiple of two or more numbers that is common to each of the numbers. Find the LCM of 4 and 6 First list the multiples of each number Multiples of 4= 4, 8, 12, 16, 20, 24, …. Multiples of 6= 6, 12, 18, 24, 30, 36, … Scan both rows of multiples and find the lowest multiple that is common to both numbers, so the LCM of 4 and 6 is… 12

How to find the HCF ‘Listing method’. . . Highest Common Factor (HCF)- The highest number that goes into two given numbers. Find the HCF of 36 and 56 36 = 1, 2, 3, 4, 6 9, 18, 36 56 - 1, 2, 4, 7, 8, 14, 28, 56 Search for the common factors and pick the highest one! HCF = 4

Find the HCF and LCM now you try. . . Find the LCM of 36 and 60 Find the LCM of 18 and 42 Find the LCM of 64 and 168 Find the HCF of 18 and 42 Find the HCF of 64 and 168 Find the HCF of 54 and 180

Find the HCF and LCM now you try. . . Find the LCM of 36 and 60 Find the LCM of 18 and 42 Find the LCM of 64 and 168 180 126 1344 Find the HCF of 18 and 42 Find the HCF of 64 and 168 Find the HCF of 54 and 180 6 8 18

How to find the HCF and LCM two numbers. 48 = 2 x 2 x 3 60 = 2 x 3 x 7 48 of HCF = 2 x 3 = 12 LCM = 2 x 3 x 2 x 7 = 336 60 To in the intersection Tofindthe the. HCF LCMmultiplythe allnumbers of the numbers in the Venn together Diagram

Practice finding the HCF and LCM using a Venn Diagram Find the HCF and LCM of the following pairs of numbers 1. 60 and 96 2. 90 and 175. 3. 84 and 180 4. 32 and 80 5. 120 and 84

Practice finding the HCF and LCM using a Venn Diagram Find the HCF and LCM of the following pairs of numbers 1. 60 and 96 HCF= 12 LCM= 480 2. 90 and 175. HCF= 5 LCM= 3150 3. 84 and 180 HCF= 12 LCM= 1260 4. 32 and 80 HCF= 16 LCM= 160 5. 120 and 84 HCF= 12 LCM= 840

Problem Solving and Reasoning 1) Barry and Sam cycle around a cycle track. It takes Barry 30 seconds to cycle around the track. It takes Sam 50 seconds to cycle around the track. If both men start cycling at the same time at the start line, how many laps will they each have cycled when they are next at the start line together? 2) Sharon wants to tile her wall which measures 216 cm by 120 cm. She is going to use grey and white square tiles alternately. The width of each tile has to be a whole number in cm. What is the largest size square tile she can use?

Problem Solving and Reasoning 1) Barry and Sam cycle around a cycle track. It takes Barry 30 seconds to cycle around the track. It takes Sam 50 seconds to cycle around the track. If both men start cycling at the same time at the start line, how many laps will they each have cycled when they are next at the start line together? B= 5 S= 3 2) Sharon wants to tile her wall which measures 216 cm by 120 cm. She is going to use grey and white square tiles alternately. The width of each tile has to be a whole number in cm. What is the largest size square tile she can use? 24 by 24 cm