Chapter 2 Decimals Exercise. This stands for (whole number). What do the following shaded diagrams represent? (a) (b) (c) (d) (e) (f) (g) (h) (i) (j Remember 0 00 = 0 of 0 2. What numbers are represented by :- (a) (b) (c) 0 5... 0... 0... (d) (e) this is chapter 2 page 7
3. What does the 2 represent in each of these numbers :- (a) 2 789 (b) 5 203 (c) 89 542 (d) 0 273 (e) 0 923 4. Arrange the following groups of numbers in order, largest first :- (a) 0 5, 0 09, 0 4, 09, 0 09. (b) 003, 0 904, 0 409, 099,, 0 80. 5. The number 326 can be thought of as follows :- 326 = unit + 3 0 + 2 00 + 6 000 or unit + 326 000 Write the following decimals in the same two ways :- (a) 52 (b) 6 23 (c) 0 809 (d) 52 9 (e) 04 6. What number is :- (a) 3 0 up from 2 4 (b) 8 00 down from 5 7 (c) 3 000 up from 2 475? 7. What number lies half way between :- (a) 0 2 and 0 8 (b) 40 and 395 (c) 2 35 and 2 325 = 0 of 0 00 0 of 00 8. Remember. What would equal as a decimal? Exercise 2 Say what number each of the arrows is pointing to :-. 2. 2 3 4 20 2 3. 4. 2 4 42 43 5. 6. 7. 7. 6 8 4 8 2 4 0 6 this is chapter 2 page 8
8. 9. 2 7 2 8 2 9 5 0 5 0.. 2. 6 8 0 2 0 4 0 6 4 2 0 0 8 Exercise 3. When each number is rounded to decimal place, which of the two values in the brackets is the correct answer : (a) 3 26 (3 2 or 3 3)? (b) 38 ( 3 or 4)? (c) 7 05 (7 0 or 7 )? (d) 8 9 (8 9 or 9 0)? (e) 2 95 (2 9 or 22 0)? (f) 0 04 (0 0 or 0 )? 2. Copy and complete, rounding each number to decimal place : (a) 3 8729 > 3... (b) 4 9999 > (c) 8 2900 > (d) 0 0502 > (e) 5 909999 > (f) 9 95078 > You may use a calculator for questions 3 to 5. 3. Write down each answer correct to decimal place :- (a) 7 (b) 30 9 (c) 0 9 4 (d) 33 34 (e) 6 4. Repeat question 3 to two decimal places. 5. Six people equally share a bingo win of 000. How much will each person get (to the nearest penny)? Exercise 4. Try to do the following mentally :- (a) 3 7 + 2 (b) 5 2 + 3 9 (c) 8 6 3 5 (d) 23 6 5 8 (e) 5 8 0 (f) 5 9 4 09 (g) 0 96 0 4 (h) 54 8-8 9 (i) 0 4 0 7 (j) 2 7 84 this is chapter 2 page 9
2. Try to do the following mentally :- (a) A 3 4 kg bag of salt is added to a 9 kg bag. (i) What is the total weight? (ii) What is the difference in weight? (b) In a formula one race Neesons track times were 2 7 and 22 56 secs. (i) What was the combined time? (ii) What was the difference in the times? 3. Copy and complete :- (a) 47 5 (b) 8 7 (c) 38 (d) + 35 2 + 5 96 7 9 38 9 89 (e) 22 4 + 9 9 (f) 4 2 3 (g) 7 3 45 (h) 5 8 4 92 4. A scientist puts 3 9 ml of hydrochloric acid, 4 56 ml of acerbic acid and 9 65 ml of citric acid into a test tube. (a) What is the total amount of acid in the test tube? (b) How much more citric than hydrochloric acid is there? 5. Perimeter is the total distance around the outside of a shape. A rectangle has length 2 32 cm and perimeter of 30 8 cm. Find the width of the rectangle (show all your working). Exercise 5. Write down the answers to the following :- (a) 8 4 x 0 (b) 9 8 x 0 (c) 7 62 x 0 (d) 8 7 x 0 (e) 6 4 x 00 (f) 0 9 x 00 (g) 4 02 x 00 (h) 0 0054 x 00 (i) 5 23 x 000 (j) 0 8765 x 000 (k) 004 x 000 (l) 4 2 x 000 2. A crate weighs 47 62 kg. What would be the weight of :- (a) 0 crates (b) 00 crates (c) 000 crates (d) 0 000 crates? 3. There are 000 millilitres in a litre. How many millilitres are there in :- (a) 5 litres (b) 7 62 litres (c) 0 045 litres (d) 0 0 litres? this is chapter 2 page 0
Exercise 6. Write down the answers to the following :- (a) 28 6 0 (b) 9 8 0 (c) 7 62 0 (d) 87 0 (e) 64 00 (f) 0 9 00 (g) 4 2 00 (h) 0 54 00 (i) 52 3 000 (j) 0 8 000 (k) 004 000 (l) 9 000 2. The length of 00 pieces of railway track is 42 6 metres long. (a) What is the length of each piece in metres? (b) Change your answer to centimetres. 3. There are 000 squibiis in a martian pound. How many martian pounds in :- (a) 3497 squibiis (b) 24 6 squibiis (c) 2977 squibiis (d) squibii? Exercise 7. Write down the answers to the following :- (a) 4 34 (b) 8 27 (c) 8 78 (d) x 4 x 7 x 6 9 38 x 9 (e) 5 7 x 8 (f) 42 3 x 4 (g) 35 9 x 5 (h) 7 x 37 52 2. Show all your working to the following questions :- (a) Fred the monkey eats 3 74 kg of food every day. What is the weight of food Fred will eat in :- (i) 3 days (ii) a week? (b) Boris the zookeeper gets paid 7 84 an hour. How much will Boris earn in :- (i) 4 hours (ii) 9 hours? (c) Kevin the Camel eats six 3 7 kg boxes of dates every month. Karen the Camel eats five 4 09 kg boxes. Who eats the most and by how much? this is chapter 2 page
Exercise 8. Copy and complete the following :- (a) 2 37 6 (b) 6 9 44 (c) 7 4 79 (d) 8 29 2 2. Find :- (a) 35 7 7 (b) 57 06 6 (c) 0 072 8 3. Show all your working for the following questions :- (a) Nine bricks have a total length of 2 6 metres long. What is the length of brick? (b) Three kegs of beer hold 307 6 litres. How much beer does one keg hold? (c) Find :- (i) a third of 20 8 (ii) a ninth of 5 66 (iii) a sixth of 6 06 (iv) a fifth of 0 7 4. Two shops sell identical shirts. Shop A sells three shirts for 8 79. Shop B sells five shirts for 4 75. Which shop has the best deal? Explain. Exercise 9 You may use a calculator for this exercise but show all working.. Shreek the ogre has eight worm lollies each 7 8 cm in length. What is the total length of all the lollies? 2. Ben has a 5 litre jug. 0 32 litres, 056 litres and 9 litres poured into it. How much more will the jug hold? 3. Senji buys six comics at 2 49 each. How much change will he get from a 20 note? 4. Marilyn buys eight concert tickets for 82. How much was it for each ticket? this is chapter 2 page 2
5. Mr. Jones borrows 2500 for a family holiday. He promises to make equal payments every 4 months for 2 years. How much is each payment? 6. A large box of Soapasud costs 2 85. A small box costs 7 98. Which is the best value? Explain your answer. Revision Exercise Soapasud Only 2 85 5 kg Soapasud Only 7 98 3 kg. What does the zero stand for in each number :- (a) 5 07 (b) 90 (c) 0 985 (d) 5 904 2. Which numbers are the arrows pointing to :- (a) (b) 8 9 3 0 3 3. Round to one decimal place :- (a) 0 849 (b) 5 79 (c) 99 50 (d) 0 6 4. Do the following mentally and write down the answer :- (a) 2 72 + 5 48 (b) 6 4 67 (c) 2 63 x 5 (d) 5 964 7 (e) 0 6 x 0 (f) 7 82 x 00 (g) 000 x 0 3247 (h) 4 32 x 200 5. A 5 metre length of cable is cut into 3 strips. The first strip was 3 42 m. The second strip was 0 75 m. How long was the third strip. 6. Use a calculator and then round to one decimal place. (a) A barrel holds 40 6 litres of water. How much would 7 barrels hold? (b) Thirteen railway cars have total length 64 2 metres. What is the length of one car? (c) A field with area 875 metres is fenced into four equal section. What is the area of each section? (d) Twenty sweets cost. How much for fifty sweets? this is chapter 2 page 3