24022021 Multiplication MATHSWATCH CLIP 19 66 GRADE 2

24/02/2021 Multiplication MATHSWATCH CLIP 19, 66 GRADE 2, 3 MULTIPLYING WITH DECIMALS

24/02/2021 Multiplication MATHSWATCH CLIP 19, 66 GRADE 2, 3 Calculating with decimals Introduction question How would you answer the following. . . ? What is the total bill if I buy a pair of jeans which cost £ 25. 90 and a bag which costs £ 13. 85 ? Challenge questions I’m curious… how did having decimal points in the question change your method? Or didn’t it? What would happen if you needed to subtract with decimals? Or multiply? Or divide?

24/02/2021 Multiplication MATHSWATCH CLIP 19, 66 GRADE 2, 3 Multiplying with decimals § First remove any decimals § Complete the calculation as normal using your favourite method § Put the decimal back in… Øcount how many digits IN TOTAL are AFTER the decimal points in the original question ØYour final answer should have the same amount of digits after its decimal point § Check your answer using an estimate

24/02/2021 Multiplication MATHSWATCH CLIP 19, 66 GRADE 2, 3 § For each question say if it is RIGHT or WRONG § Make sure that you can EXPLAIN WHY!

24/02/2021 Multiplication Question 1 0. 8 x 0. 4 = 0. 32 RIGHT MATHSWATCH CLIP 19, 66 GRADE 2, 3

24/02/2021 Multiplication Question 2 0. 3 x 0. 5 = 1. 5 WRONG MATHSWATCH CLIP 19, 66 GRADE 2, 3

24/02/2021 Multiplication Question 3 0. 5 x 0. 6 = 30 WRONG MATHSWATCH CLIP 19, 66 GRADE 2, 3

24/02/2021 Multiplication Question 4 0. 1 x 0. 1 = 0. 01 RIGHT MATHSWATCH CLIP 19, 66 GRADE 2, 3

24/02/2021 Multiplication Question 5 0. 7 x 0. 9 = 0. 63 RIGHT MATHSWATCH CLIP 19, 66 GRADE 2, 3

24/02/2021 Multiplication Question 6 0. 8 x 0. 2 = 1. 6 WRONG MATHSWATCH CLIP 19, 66 GRADE 2, 3

24/02/2021 Multiplication Question 7 0. 3 x 0. 3 = 0. 09 RIGHT MATHSWATCH CLIP 19, 66 GRADE 2, 3

24/02/2021 Multiplication MATHSWATCH CLIP 19, 66 GRADE 2, 3 Question 8 0. 8 x 0. 7 = 0. 056 WRONG

24/02/2021 Multiplication Multiplying with decimals Example Work out 1. 7 x 3 MATHSWATCH CLIP 19, 66 GRADE 2, 3

24/02/2021 0. 6 1) 2 x 0. 3 4) 0. 4 7) MATHSWATCH CLIP 19, 66 GRADE 2, 3 Multiplication 2. 4 2) 4 x 0. 6 5) 0. 2 0. 15 x 2 8) 10) 0. 02 x 3 13) 3. 2 3) 8 x 0. 4 6) 0. 8 0. 12 x 3 9) 4 x 0. 22 11) 0. 04 x 5 12) 0. 06 x 3 5 x 0. 03 14) 7 x 0. 04 15) 8 x 0. 01 16) 0. 2 x 0. 3 17) 0. 3 x 0. 5 18) 0. 4 x 0. 2 19) 0. 6 x 0. 4 20) 0. 9 x 0. 2 21) 0. 8 x 0. 3 22) 0. 12 x 0. 02 23) 0. 14 x 0. 04 24) 0. 3 x 0. 04 25) 0. 2 x 0. 01 26) 0. 5 x 0. 05 27) 0. 2 x 0. 001 28) 0. 4 x 0. 003 29) 0. 2 x 0. 3 x 0. 4 30) 0. 3 x 0. 2 x 0. 5 31) ( 0. 2 ) 32) ( 0. 2 ) 33) ( 0. 1 ) 34) ( 0. 2 ) x 0. 1 35) ( 0. 1 ) x ( 0. 2 ) 2. 8 x 7 0. 3 0. 06 0. 15 0. 06 0. 24 0. 002 0. 0012 0. 042 0. 0008 3 1. 4 x 7 0. 36 0. 28 0. 15 0. 18 0. 0056 0. 025 0. 024 0. 008 3 0. 0004 2 2 4 x 5 0. 88 0. 18 0. 08 0. 24 0. 012 0. 0002 0. 03 0. 001 3

24/02/2021 Multiplication Multiplying with decimals Example Calculate 12. 5 x 4 Extension – Tell me what the following would be… a) 1. 25 x 0. 4 b) 125 x 40 c) 0. 125 x 0. 4 MATHSWATCH CLIP 19, 66 GRADE 2, 3

24/02/2021 Multiplication Multiplying with decimals Example Work out 2. 35 x 12 Extension – Tell me what the following would be… a) 2. 35 x 1. 2 b) 235 x 0. 12 c) 23. 5 x 0. 012 MATHSWATCH CLIP 19, 66 GRADE 2, 3

24/02/2021 Multiplication MATHSWATCH CLIP 19, 66 GRADE 2, 3 Multiplying with decimals ALL 1. a) 3. 2 x 4 = b) 6. 5 x 8 = c) 9. 3 x 7 = d) 2. 8 x 9 = e) 7. 4 x 5 = f) 1. 2 x 3 = g) 12. 3 x 7 = MOST 2. a) 8. 25 x 6 = b) 9. 73 x 4 = c) 4. 68 x 8 = d) 2. 17 x 2 = e) 3. 71 x 7 = f) 7. 45 x 9 = g) 2. 87 x 5 = SOME 3. a) 8. 25 x 33 = b) 7. 12 x 19 = c) 2. 48 x 46 = d) 5. 74 x 34 = e) 6. 21 x 51 = f) 4. 69 x 84 = g) 3. 84 x 65 = h) 2. 65 x 182 = i) 5. 27 x 483 = j) 2. 93 x 523 = k) 4. 46 x 267 = l) 8. 21 x 384 =

24/02/2021 Multiplication MATHSWATCH CLIP 19, 66 GRADE 2, 3 Worded Problems! 1) You buy two movie tickets at £ 8. 75 each, what will your change be from £ 20? 2) You go to breakfast with your friend, a small tea is £ 2. 50 and a bagel with cream cheese is £ 3. 75. If you pay with £ 20, how much change will you receive? 3) One bottle of coke costs £ 1. 72. How much will 6 bottles cost? 4) At a tea shop, one slice of cake costs £ 2. 39. Mr Wallace wants the whole cake to himself, there are eight slices altogether, how much will it cost? 5) It costs £ 237. 12 to hire a coach to Alton Towers. But the school needs to work out how much it will cost to take 12 coaches? Can you work out the answer? 6) I’m currently doing up my house and I need new skirting boards round my living room. I need 4 lengths, these are as follows 2. 3 m, 4. 2 m, 3. 7 m and 2. 8 m, it costs £ 4. 76 per metre. How much will it cost in total?