Page 60 - Start Up Mathematics_7

2. Recognize the pattern and write the next three terms:
(a) 0.1, 0.4, 0.7, 1.0, ________, ________, ________

(b) 0.3, 1.5, 2.7, 3.9, ________, ________, ________
(c) 0.4, 0.8, 1.6, 3.2, ________, ________, ________
(d) 2.2, 1.1, 0.55, 0.275, ________, ________, ________

(e) 3.6418207, 3.641820, 3.64182, 3.6418, ________, ________, ________

Changing Fractions to Decimals

1. In each of the following figures, find the decimal number representing the shaded region.

(a) (b) (c) (d)

[Hint: First find the fraction representing the shaded region and then find its equivalent
decimal number upto 3 places.]

2. Is the decimal number representing the shaded region in Fig. 1(b) above different from
others?

At a Glance

1. A decimal number has two parts, the whole part and the decimal part.

2. Decimal places in a decimal number are the number of digits on the right of the decimal
point.
3. Like decimals are those which have same number of decimal places.

4. Unlike decimals are those which have different number of decimal places.
5. Unlike decimals can be converted into like decimals by adding zeros on the right side of the
decimal part.
6. In order to compare two decimal numbers, we first see their whole part. The number having
a greater whole part is greater. If the whole part is same, we compare their tenth parts. The
number having a greater tenth part is greater. If the tenth part is same, we compare their
hundredth parts and so on till one of the parts is greater. The number corresponding to the
first greater part is greater.

7. Decimal numbers can be added or subtracted by converting them into like decimals. Write
the numbers in columns according to the place value and the decimal point directly below
one another. Now add or subtract as we add or subtract whole numbers.
8. To multiply a decimal number by 10, 100 or 1,000, ...., the digits remain the same, but the
decimal point shifts respectively one, two or three and so on places to the right.

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