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Practice time 1e

1. Round off each of the following numbers to the nearest 10.
( a) 75 (b) 247 (c) 865 (d) 4242

( e) 6052 (f) 8873 (g) 68744 (h) 508379

2. Round off each of the following numbers to the nearest 100.
( a) 414 (b) 584 (c) 7650 (d) 8899

( e) 17209 (f) 28769 (g) 120111 (h) 318574

3. Round off each of the following numbers to the nearest 1000.
( a) 9373 (b) 8720 (c) 107898 (d) 36509
( e) 218942 (f) 58975 (g) 1035609 (h) 2867366

4. Round off each of the following numbers to the nearest: i. 10, ii. 100, iii. 1000.

( a) 52670 (b) 37645 (c) 25893 (d) 41982

( e) 547125 (f) 258356 (g) 362780 (h) 1670248

roman numeraLs

In Roman numerals, seven symbols are used to represent numbers. These symbols and
their corresponding Hindu-Arabic numerals are given below.

Roman numeral I V X L C d M

Hindu-Arabic numeral 1 5 10 50 100 500 1000

rules for writing roman numerals
Be Aware
Rule 1: Repetition of a Roman numeral means addition. There is no symbol for zero in

Examples: (a) III = 1 + 1 + 1 = 3 the Roman number system.

( b) XXX = 10 + 10 + 10 = 30
( c) CC = 100 + 100 = 200

Rule 2: A smaller Roman numeral on the right of a larger Math Insight
Roman numeral is always added to the larger Š I, X, C and M can be repeated
only thrice.
Roman numeral. Š V, L and D cannot be repeated.

Examples: (a) XIII = 10 + 1 + 1 + 1 = 13 Š I can be subtracted only from
V and X.
( b) XXV = 10 + 10 + 5 = 25 Š X can be subtracted only from
L and C.
( c) CXX = 100 + 10 + 10 = 120 Š C can be subtracted only from
( d) DLX = 500 + 50 + 10 = 560 D and M.

( e) MCCX = 1000 + 100 + 100 + 10 = 1210 Š V, L and D are never
subtracted.

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