290 likes | 516 Vues
Mathematics Workshop Year 5. Helping your child with Maths calculations. Think back to the Maths you were taught at primary school. In what situations do you use this Maths now?. Shopping – estimating if you have enough money Finding 25% off in a sale
E N D
Mathematics WorkshopYear 5 Helping your child with Maths calculations
Think back to the Maths you were taught at primary school. In what situations do you use this Maths now?
Shopping – estimating if you have enough money • Finding 25% off in a sale • Splitting the bill in a restaurant • Measuring for fitting at home • Cooking – times and temperatures • Timing journeys • Changing currency
1999 A new approach to teaching Mathematics • Strong emphasis placed on mental strategies – time allocated in all lessons • Children learn in different ways and prefer different methods • A real understanding of numbers
video clip Arrow cards, place value
Ask… 1. Can I do this in my head? 2. Could I use drawings or informal jottings to help me? 3. Do I need to use a formal written method? 4. Should I use a calculator?
ADDITIONHow would you calculate these? 256 + 627 = 53523 +2346 =
ADDITION – EARLY STEPS 1. Partitioning: E.g. 256 + 627 = Hundreds: 200 + 600 = 800 Tens: 50 + 20 = 70 Units: 6 + 7 = 13 800 + 70 + 13 = 883
ADDITION – LATER STEPS 2. Column addition: E.g. 53523 + 2346 = 53523 53523 2346 + 2346 + Units 9 55869 Tens 60 Hundreds 800 Thousands 5000 Ten thousands 50000 Total 55869 Ensure the place value is correct i.e. T H T U
Final steps: Can the children APPLY these addition skills? Fred went to Bahrain to see the Grand Prix. He had AED6500 for the trip. It cost him AED480 for his ticket, AED2136 to stay 2 nights at a hotel, AED3449 for his flight and AED240 for food. Did he have enough money? The exact same method is used when adding decimals . Just ensure that the decimal stays in the same place in the question and answer.
He had AED6500, he spent AED6305 so yes, he had enough money! 1 2 1 480 2136 3449 240 6305
SUBTRACTIONHow would you calculate these? 873 - 791 = 8456 - 3938=
SUBTRACTION – EARLY STEPS 1. Using an empty number line: E.g. 873 – 791 = (Count forward from the smaller number to the bigger) + 9 + 70 + 3 791 800 870 873 9 + 70 + 3 = 82
SUBTRACTION – LATER STEPS 2. Column subtraction e.g. 8456 – 3938 = 7000 1 40 1 8000 + 400 + 50 + 6 - 3000+ 900 + 30 + 8 4000 + 500 + 10 + 8 = 4518 7 1 4 1 8456 3938 - 4518
Applying our subtracting skills… £9.65 £6.50 £1.25 £2.80 I head to the sports shop with £20.00. I buy a cricket bat and a cricket ball. How Much change do I get?
Step 1Step 2 1 £ 9.65 £20.00 - £10.90 £ 1.25 + = £9.10 £ 10.90
MULTIPLICATION AND DIVISION • Importance of knowing times tables • Division facts E.g. if 5 x 7 = 35 then 35 ÷ 7 = 5
Multiplying and dividing by 10 27 ÷ 10 = 2.7 5.9 x 10 = 59 368 ÷ 10 = 36.8
MULTIPLICATION – EARLY STEPS • Use known facts: • Use your times tables: E.g. 15 x 7 = 10 x 7 + 5 x 7 = • Use your doubling skills: E.g. 35 x 4 = 35 x 2 = 70 70 x 2 = 140
MULTIPLICATION – EARLY STEPS 2. Grid Method E.g. 346 x 9 2700 + 360 + 54 3114 1 1
MULTIPLICATION – LATER STEPS 3. Column method: e.g. 72 x 38 1 72 x 38 576 2160 2736 1 72 x 38 16 8 x 2 560 8 x 70 60 30 x 2 + 210030 x 70 2736 1
Applying your multiplication… 27 children pay AED 55 for a school trip to the planetarium. How much money is paid in total? AED 10 was to pay to the bus company and the rest was to pay to the Planetarium. How much money did the planetarium take in total?
PART 2 10 x 27 = 270 for the buses 1485 – 270 = AED 1215 for the planetarium in total 27 x 55 1000 + 100 + 350 + 35 = AED 1485 in total
DIVISION – EARLY STEPS, CHUNKING 196 ÷ 6 196 - 180 (30x 6) 16 - 12 (2x 6) 4 Answer: 32 remainder 4 or 32 r 4 196 60 (10 x 6) 136 60 (10 x 6) 76 60 (10 x 6) 16 12 (2 x 6) 4
DIVISION – MUCH LATER STEPS 365 ÷ 15 = 24 r5 2 4 r5 15 365 3 0 6 5 6 0 5 Finally: 24 r5 6 15 365
Apply these division skills… A netball team is made up of 7 players. If 212 children turn up to a netball tournament, how many full teams could you make?
How many teams?212 ÷ 7 = 212 70 (10 x 7) 142 70(10 x 7) 72 70(10 x 7) 2 So you can make 30 full teams. There will be 2 players left over.
Is my answer sensible? 1. Estimate the answer - can they round up the numbers to come up with a rough answer? E.g. 47 x 2 = Estimate: 50 x 2 = 100 Once you have calculated the answer ask yourself, “Is it close to the estimate?” 2. Check the answer using the inverse - E.g. 47 x 2 = 94 so 94 ÷ 2 = 47.
What now? • www.gemslearninggateway.com – - Notes from today - ‘Helping you to help your child with Maths booklet’ - Calculation booklets with these methods explained in detail - Useful websites - Mental Maths passports • jsmith@jpsdubai.sch.ae