9q1 Homework 17 Due Wednesday 17/2 /11 1. Check previous homework & complete corrections 2. Revise topics covered this term – see table and example questions on the next page. Shape & Space: • Use units of measurement to calculate, estimate, measure and solve problems in a variety of contexts; convert between area measures (mm 2 to cm2, cm2 to m2, • • etc). Know and use the formulae for the circumference and area of a circle. Calculate the surface area and volume of right prisms. Number: • multiply and divide by any integer power of 10 (100, 1000, etc) • Use rounding to make estimates; round numbers to the nearest whole number or to one or two decimal places. • Know that a recurring decimal is a fraction. • Use standard methods to add and subtract integers and decimals of any size, including a mixture of large and small numbers with differing numbers of decimal places. • multiply and divide by decimals, dividing by transforming to division by an integer (eg divide by 3 instead of 0.003, then move the decimal in the answer) • Check answers using appropriate methods • Use a calculator efficiently and appropriately to perform complex calculations with numbers of any size, knowing not to round during intermediate steps of a calculation; use the constant, p and sign change keys, function keys for powers, roots and fractions, brackets and the memory. • Enter numbers into a calculator and interpret the display in context (negative numbers, fractions, decimals, percentages, money, metric measures, time). • Solve substantial problems by breaking them into simpler tasks, using a range of efficient techniques, methods and resources, including ICT; • use trial and improvement where a more efficient method is not obvious. The next page has a question or 2 from each topic – Answers are at the end of the document. Shape & Space: • Use units of measurement to calculate, estimate, measure and solve problems in a variety of contexts; convert between area measures (mm 2 to cm2, cm2 to m2, etc). Q – Show that 4 hours 15 minutes is the same as 255 minutes Q – A bathroom tile measures 10 cm by 10 cm. How many do you need for a shower cubicle with wall area of 3 m2? Q – 2m 11mm 24cm 0.8mm 80cm Which of these distances would be about right for: a) length of a maths exercise book b) thickness of a pencil c) height of a door d) Thickness of a bank / credit card e) Width of a door • Know and use the formulae for the circumference and area of a circle. Q – Find the area and circumference of a circle with diameter 40 cm Q – What is the radius of a circle whose circumference is 3m? Q – Find the shaded area on the circle pictured. • Calculate the surface area and volume of right prisms. Q – What is the surface area and volume of a cereal box measuring 6 cm deep by 20 cm wide by 45 cm tall? Q – Find the surface area and volume of the triangular prim below Q – Find the volume of the cylinder to the right. Number • multiply and divide by any integer power of 10 (100, 1000, etc) Q– 0.03 x 10,000 = 80 ÷ 1000 = • • Use rounding to make estimates; round numbers to the nearest whole number or to one or two decimal places. multiply and divide by decimals, dividing by transforming to division by an integer (eg divide by 3 instead of 0.003, then move the decimal in the answer) Q - £460 ÷ 9 0.003 x 0.4 2500 x 30 0.006 x 20 50kg ÷ 12 (give answer to nearest 10 grams) • Know that a recurring decimal is a fraction. Q – What is 1/3 as a decimal? What is 3/11 as a decimal? • Use standard methods to add and subtract integers and decimals of any size, including a mixture of large and small numbers with differing numbers of decimal places. Q – I have £1,236.35 in my bank. I earn £210 in wages, spend £450 on rent for the month and £6.78 on food for dinner. How much have I got left? • • Check answers using appropriate methods Use a calculator efficiently and appropriately to perform complex calculations with numbers of any size, knowing not to round during intermediate steps of a calculation; find powers, roots and fractions, Q – use a calculator to find √20 - write down the full calculator display. • Enter numbers into a calculator and interpret the display in context (negative numbers, fractions, decimals, percentages, money, metric measures, time). • Solve substantial problems by breaking them into simpler tasks, using a range of efficient techniques, methods and resources, including ICT; • use trial and improvement where a more efficient method is not obvious. Q - What number cubed gives the answer 343000? Q – Which chamber of the revolver has a bullet in it? Shape & Space: • Use units of measurement to calculate, estimate, measure and solve problems in a variety of contexts; convert between area measures (mm 2 to cm2, cm2 to m2, etc). Q – Show that 4 hours 15 minutes is the same as 255 minutes 4 x 60 = 240 240 + 15 = 255. Q – A bathroom tile measures 10 cm by 10 cm. How many do you need for a shower cubicle with wall area of 3 m2? Each 1 m2 can fit 10 tiles across and 10 tiles up = 100 tiles per square metre. There are 3 square meters = 300 tiles (assuming no breakages, cutting of tiles or corners in the shower) Q – 2m 11mm 24cm 0.8mm 80cm Which of these distances would be about right for: a) length of a maths exercise book 24cm b) thickness of a pencil 11mm c) height of a door 2m d) Thickness of a bank / credit card 0.8mm e) Width of a door 80 cm • Know and use the formulae for the circumference and area of a circle. Q – Find the area and circumference of a circle with diameter 40 cm A = π x r2 = 3.14 x 202 = 3.14 x 400 = 1256.00 = 1256cm2 C = 2 x π x r = 2 x 3.14 x 20 = 125.6 cm Q – What is the radius of a circle whose circumference is 3m? 3=2xπxr 1.5 = π x r r = 1.5 ÷ π = 0.4777 m Q – Find the shaded area on the circle pictured. Big Circle A = π x r2 = 3.14 x 52 = 78.5 cm2 Small (inner) circle A = π x r2 = 3.14 x 32 = 28.3 cm2 Shaded Area = 78.5 – 28.3 = 50.2 cm2 • Calculate the surface area and volume of right prisms. Q – What is the surface area and volume of a cereal box measuring 6 cm deep by 20 cm wide by 45 cm tall? V = (area at end) x length = 6 x 20 x 45 = 5400 cm 3 Surface area = Find area of each side & add all together SA = 120 + 120 + 900 + 900 + 270 + 270 = 2580cm2 Q – Find the surface area and volume of the triangular prism below? V = (area at end) x length V = (½ x 5 x 12) x 7 = 30 x 7 = 210 cm2 Surface Area Add up the area of all 5 sides (½ x 5 x 12) + (½ x 5 x 12) + (5 x 7) + (12 x 7) + (13 x 7) 30 + 30 + 35 + 84 + 91 = 270 cm2 SA = 270 cm2 Q – Find the volume of the cylinder to the right. V = (area at end) x length = π x r2 x length = 3.14 x 0.52 x 19 = 14.9 cm3 Number • multiply and divide by any integer power of 10 (100, 1000, etc) Q– 0.03 x 10,000 = 300 80 ÷ 1000 = 0.08 • • Q- Use rounding to make estimates; round numbers to the nearest whole number or to one or two decimal places. multiply and divide by decimals, dividing by transforming to division by an integer (eg divide by 3 instead of 0.003, then move the decimal in the answer) £460 ÷ 9 = £51.11 2500 x 30 = 75,000 0.003 x 0.4 = 0.0012 0.006 x 20 = 0.12 . 50kg ÷ 12 (give answer to nearest 10 grams) 50 ÷ 12 = 4.16666 Answer – 4.16666.... kg rounds to 4.17 kg (or 4170g) • Know that a recurring decimal is a fraction. . Q– What is 1/3 as a decimal? 0.33 .. Q– • What is 3/11 as a decimal? 0.272727272 = 0.27 Use standard methods to add and subtract integers and decimals of any size, including a mixture of large and small numbers with differing numbers of decimal places. Q – I have £1,236.35 in my bank. I earn £210 in wages, spend £450 on rent for the month and £6.78 on food for dinner. How much have I got left? 1 236.35 + 210 = 1 446.35 1446.35 – 450 = 996.35 996.35 – 6.78 = £989.57 • Check answers using appropriate methods • Use a calculator efficiently and appropriately to perform complex calculations with numbers of any size, knowing not to round during intermediate steps of a calculation; find powers, roots and fractions, Q – use a calculator to find √20 - write down the full calculator display. Press the buttons √ 2 0 = OR 2 0 √ Then write down full display ( 4.472135 – you might have a couple more or less digits on your display) • • • Enter numbers into a calculator and interpret the display in context (negative numbers, fractions, decimals, percentages, money, metric measures, time). Solve substantial problems by breaking them into simpler tasks, using a range of efficient techniques, methods and resources, including ICT; use trial and improvement where a more efficient method is not obvious. Q - What number cubed gives the answer 343 000? Try10... 103 = 1 000... try 100...1003 = 1 000 000 … 503 = 125 000 … 803 = 512 000 703 = 343 000! cube root of 343 000 = 70. Q – Which chamber of the revolver has a bullet in it? The last one.