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Division Using multiplication and traditional short division What’s It All About? You are going to learn: How to divide by inversing multiplication and using traditional short division. What skills should you have already? You need to be able to multiply and subtract two values using a written method. Division Remember that 6 ÷ 3 means “how many threes make 6?” Division is the INVERSE of Multiplication. There are different ways of showing division. 6÷3 6 3 The answer is the same in all three cases! 3 6 Using Multiplying to Divide For multiplying, we can use a grid like this: 2 3 4 5 6 1 2 2 4 3 6 4 8 5 6 7 8 9 10 12 14 16 18 3 4 5 6 9 12 15 18 21 24 27 8 12 16 20 24 28 32 36 10 15 20 25 30 35 40 45 6 12 18 24 30 36 42 48 54 We can now use it to divide as well as multiply. Example: 20 4 means “How many 4’s make 20?” The answer is 5 Your Turn Remember that 6 ÷ 3 means “how many threes make 6?” Work out: 1. 16 ÷ 4 2. 30 ÷ 5 3. 30 ÷ 10 4. 45 ÷ 9 5. 72 ÷ 8 6. 21 ÷ 3 7. 21 ÷ 7 Traditional Short Division 1 Find the answer to £84 ÷ 4 How many 4’s make 84? Set up the division: 2 1 4 84 You have 8 ten pound notes to share between 4 people. How many do they get each? You have 4 one pound coins to share between 4 people. How many do they each get? £84 ÷ 4 = 21 Traditional Short Division 2 Work out 312 ÷ 12 How many 12’s make 312? Set up the division: 2 12 331 2 You have 3 one hundred pound notes to share between 12 people. Can you share out the notes? No Change them into ten pound notes... This question is not about money, but it is easier if you think of it in that way... You have 31 ten pound notes to share between 12 people. How many do they each get? 12 2 = 24 and 12 3 = 36 How many notes are left? 31 – 24 = 7 Traditional Short Division 2 Work out 312 ÷ 12 Set up the division: 2 6 12 33172 How many notes are left? 31 – 24 = 7 Change them into one pound coins. You have 72 one pound coins to share between 12 people. How many do they each get? 12 6 = 72 312 ÷ 12 = 26 Traditional Short Division 3 Work out 484 ÷ 11 How many 11’s make 484? Set up the division: 4 11 448 4 You have 4 one hundred pound notes to share between 11 people. Can you share out the notes? No Change them into ten pound notes... You have 48 ten pound notes to share between 11 people. How many do they each get? 11 4 = 44 and 11 5 = 55 How many notes are left? 48 – 44 = 4 Traditional Short Division 3 Work out 484 ÷ 11 How many 11’s make 484? Set up the division: 4 4 11 44844 Change them into one pound coins. You have 44 one pound coins to share between 11 people. How many do they each get? 11 4 = 44 484 ÷ 11 = 44 How many notes are left? 48 – 44 = 4 Your Turn Remember that 6 ÷ 3 means “how many threes make 6?” Work out: 1. 728 ÷ 8 2. 219 ÷ 3 3. 21749 ÷ 7 4. 384 ÷ 12 5. 2190 ÷ 10 6. 273 ÷ 13 7. 2310 ÷ 11 End