Addition & subtraction
In spoken English, 2 + 3 = 5 is, ‘Two plus two equals five’ or ‘Two plus three is equal to five’ or ‘Two plus three is five’ or ‘Two increased by three equals five’. This arithmetical operation is called addition. The result of this operation is called the sum. Thus, if two is added to three, the sum is five.
In spoken English, 5 – 3 = 2 is, ‘Five minus three equals two’ or ‘Five minus three is equal to two’ or ‘Five minus three is two’ or ‘Five decreased by three equals two’. This arithmetical operation is called subtraction. The result of this operation is called the difference. Thus, if three is subtracted from five, the difference is two.
Multiplication & division
In spoken English, 4 × 2 = 8 is, ‘Four multiplied by two equals eight’ or ‘Four times 4 equals eight’. This arithmetic operation is called multiplication. The result of this operation is the product. Thus, if four is multiplied by two, the product is eight.
In spoken English, 8 : 2 = 4 is, ‘Fight divided by two equals four’. This arithmetical operation is called division. The result of this operation is called the quotient. Thus, if twelve is divided by two, the quotient is six.
In pairs, look at the highlighted words and phrases. Try to guess what they mean from the context. Then check with your dictionary or teacher. Work out the list of the terms involved, make a kind of glossary.
In pairs, read the numerical expression to your partner and ask him/her what operation is done. Your partner will fill in the blank with the operation s/he hears.
| Expression | What operation is done? |
| Ten multiplied by forty | It is… |
| Two times eighty-one | It is… |
| Twelve decreased by eight | It is… |
| One subtracted from eighteen | It is… |
| Eleven divided by fifteen | It is… |
| The product of twelve and eight | It is… |
| The quotient of ninety-one and fifty | It is… |
| Forty-two added to seventeen | It is… |
| Sixteen increased by eleven | It is… |
| The difference of fifty-three and thirty-seven | It is… |
Use the sentences below as models and make up four questions. Let your group-mates answer them.
a. If eight is subtracted from ten, what is the difference?
b. If 379,252 is added to 8,148, what is their sum?
c. If 10 is divided by 2, what is the quotient?
Practise asking your classmates similar questions and giving full answers about the operations listed below.
1. 394 : 2 =
2. 64 : 4 =
3. (40 + 20) : 3 =
4. (15 + 17) × 2 =
5. (41 - 3) : 19 =
6. 
Unit 3
THE BEST TIME TO DO EVERYTHING
Reading and Vocabulary
1. Match the explanations/definitions in A (1–7) with the words in B (a–g):
| A | B | ||
| large, reddish – brown organ in the body which secretes bile and purifies the blood | a | metabolism | |
| in a sudden way | b | siesta | |
| (of food) changed, be changed in the stomach | c | delicious | |
| process by which food is built up into living matter or by which living matter is broken down into simple substances | d | indigestion | |
| giving delight, tasty | e | digestive | |
| (pain from) difficulty in digesting food | f | liver | |
| period of rest or sleep taken in the early afternoons, as is customary in hot countries | g | dramatically |
Read the article and complete it with a word from the task 1 (column B).
Expert opinion
The new science of chronobiologytells us the best time of the day to do everything, from writing a poem to taking pills.
By following your body’s natural daily rhythms, you can get more out of every day.
| 7 a.m. – 9 a.m. | Have a good breakfast. The 1_____ is at its most active in the morning, and everything you eat at this time gives you energy but doesn’t make you put on weight. It’s also the best time of the day to take vitamins. If you take them in the afternoon or evening, some vitamins can cause2_____ or keep you awake |
| 9 a.m. – 10 a.m. | Go to the doctors or dentists. Injections are least painful at this time of the day |
| 10 a.m. – 12 | Work, study, paint a picture or write a poem. The brain is at its most creative at this time of the day |
| 12 – 2 p.m. | Eat. This is the best time of the day to have lunch. The 3_____ system works very efficiently at this time. You should have your big meal of the day now, and not in the evening |
| 2 p.m. – 3 p.m. | Have a4_____. After lunch the body temperature goes down and the brain works more slowly. There are a lot of road accidents at this time of the day because drivers fall asleep at the wheel |
| 3 p.m. – 5 p.m. | Go to the gym. Physically our body is at its peak now. Most Olympic records are broken at this time of the day |
| 4 p.m. – 6 p.m. | Do homework, especially maths. Research shows that children are better at arithmetic at this time of the day |
| 6 p.m. – 8 p.m. | Eat and drink (in moderation) and enjoy yourself. Our sense of smell and taste are at their best at this time, so now is the moment for a light but5_____ dinner. The 6_____ is also at its most efficient in dealing with alcohol, so it’s also the best time of the day to have a glass of wine. It is also the time when the skin absorbs cream best, so before dinner is the time to put on face or body cream |
| 8 p.m. – 10 p.m. | Phone your friends. This is the time of the day when people most often feel lonely (and it’s also cheaper to phone in many parts of the world) |
| 10p.m. – 11p.m. | Get ready for bed. One of the best ways to make sure you will sleep well is to have a hot bath, which will relax your mind and body |
| 11p.m. – 7a.m. | Sleep. After 11 o’clock, the metabolismslows down, preparing us for sleep. If we stay awake after midnight, our attention drops 7_______, and this is the time of the day when people find it most difficult to concentrate if they are studying or working |
Дата: 2016-10-02, просмотров: 243.
