IPT Exercises 4.10 #4-10

4.10 Exercises

4. Write programs to calculate:
a. the area of a circle of radius 10 m,
Chapter 4 : Simple Programs 85

b. the annual interest payable on a loan of $5365.25 at
12.5%, and

c. the sales tax payable at 7% on a purchase of $12.50.
In the last two examples the answers are not rounded off to
the nearest cent. You can force this by indicating not only the
field size but the numbers of decimal places to be output. For
put 1.66666 : 5 : 2
will produce °1.67. The 2 indicates that you want 2 decimal
places. The last decimal digit is rounded off. Change the
programs for parts b and c to output values to the nearest

5. Experiment to see what happens when you specify a field size
which is too small to hold a number. For example, try this
put "How many digits ", 1 / 3 : 5
put "What about this?": 8

6. What happens when you work with very big numbers? Try this
put 32516 * 578632.0
Try others. When the result is output, it is in the exponent
form, often used in science. Try leaving the decimal point off
the second number.

7. What happens when you work with very small numbers. Try
this example
put 0.0000003 * 0.000006
Try others. The exponents or powers of 10 are negative.

8. Try a program with the ** arithmetic operator
put 7 ** 2, " is the same as ", 7 * 7
The ** is the operator for exponentiation. Try other

9. Use the exponent form of real numbers in an arithmetic
expression. For example,
put 6e5 + 2e2, " is the same as ", 600000 + 200
When is the answer output in exponent form? Experiment
using other examples.

10.In Turing there are a number of mathematical functions
predefined in the language. Try this
put "The square root of 49 is ", sqrt (49)
The sqrt function produces the square root of what follows in
parentheses. Try this
put sqrt (371 ** 2)
Experiment with the square root function.