1. Chapter Four
Numbers:
Everyone’s language

2. Match the words with the pictures, signs and numbers:
a. ＋ b c. 5/8 d.  e.  f. ＝ g
h i j. 90 k. × l.
m n. 45%
a decimal number subtract; minus
2. a protractor multiply
(for measuring angles) divide
3. a pair of odd numbers a number showing
4. compasses degrees
(for drawing circles) a percentage
5. a fraction a pair of even
6. zero numbers
7. add; plus equals d m h k e g l j n c b i a f

3. Read the article and tell whether the following statements are true or false.
( ) 1. In ancient times, numbers were written in
different ways, but counting was nearly
always in tens.
( ) 2. Everyone uses the numbers system 1 to 9
plus 0 (zero).
( ) 3. The numbers system was invented by the
Chinese.
( ) 4. Zero makes it even more difficult to write
big numbers and to calculate.
( ) 5. People use abacuses, calculators and
computers to calculate.
( ) 6. Calculators cannot calculate percentages
and square roots.
( ) 7. Computers can work only when human
beings program them with instructions. T T F F T F T

4. equal(s) v. add v. Add…and…. plus prep. …plus…is….+
add v. Add…and….
plus prep. …plus…is…. -
subtract v. Subtract…from….
minus prep. …minus…is….
equal(s) v. is =

5. multiply v. Multiply…by…. …multiplied by…is…. times prep. …times…is….×
multiply v.
Multiply…by….
…multiplied by…is….
times prep.
…times…is….

6. divide v.
Divide…by….
…divided by…is…. ÷

7. statements 陈述，说明 instructions 指示，指令 Add one and one 1+1
One plus one equals two =2
prep.
Two minus one equals one =1
Two multiplied by three is six *3=6
adj.
Four divided by two is two ÷2=2
statements
陈述，说明
Add one and one
Subtract one from two
Multiply two by three *3
Divide four by two ÷2 v.
instructions
指示，指令

8. ＋ plus  minus × multiply/multiplied  divide/divided
2 ＋ 3 ＝ 5
5  2 ＝ 3
2 × 3 ＝ 6
6  2 ＝ 3
2 plus 3 equals/is 5.
5 minus 2 equals/is 3.
2 multiplied by 3 equals/is 6
6 divided by 2 equals/is 3.

9. 8 1 2 4 A game: 24 points ＋ plus minus  × multiply  divide 8  2 ＝6
equals/is 6.
6 × 4 ＝24
6 multiplied by 4 equals/is 24. 2 4
24 1 ＝24
24 divided by 1 equals/is 24.

10. A game: 24 points 5 2 ＋  × 
plus
minus
multiply
divide 1 7

11. A game: 24 points 4 5 ＋  × 
plus
minus
multiply
divide 9 5

12. A game: 24 points 3 2 ＋  × 
plus
minus
multiply
divide 6 8

13. A game: 24 points 2 6 ＋  × 
plus
minus
multiply
divide 4 8

14. Homework
Recite the second paragraph
Do exercise 2