Page 20 - Maths Class 06

Exercise 1.3

1. Write the following in Roman numerals:
(a) 45 (b) 92 (c) 68 (d) 105
(e) 375 (f) 549 (g) 174 (h) 299

(i) 601 (j) 835 (k) 1759 (l) 2090
2. Write the following in Hindu-Arabic numerals:
(a) CDXXX (b) MCMV (c) CLV (d) LXXVII
(e) DLXIX (f) CDXXXIX (g) CCXLII (h) CLXVII
3. Arrange the following in ascending order:

(a) XXXI, XL, XXI, XXIV, XLV (b) DXLIV, CDXLV, DXXIX, DXCIX
4. Arrange the following in descend ing order:
(a) XXXVIII, XXXII, XLIX LVIII (b) DCXXXV, CXLI CCCLIV, CDXXIX

At a Glance

l Out of two numbers, the one having more number of digits is greater.
l If two numbers have same number of digits, we compare them by comparing extreme left digits. In
case, they care also same, we compare them by their next digit to the right and so on.
l In Indian system of numeration, the periods are crores, lakhs, thousands and units while in
international system of numeration, these are millions, thousands and units.

l 1 km = 1,000 m = 1,00,000 cm = 10,00,000 mm
1 kg = 1,000 g = 10,00,000 mg; 1 kL = 1,000 L = 10,00,000 mL; 1 year = 365 days = 8760 hrs.
l For rounding off a number to the nearest 10, 100, 1000…, etc. We look at the digit at a lower place,
i e. ., ones ten, hundreds,…, etc. If the digit at the ones, tens or hundreds is less than 5, the number is
rounded off downwards otherwise upwards.
l Roman numeration system has seven basic symbols as:

I for 1, V for 5, X for 10, L for 50, C for 100, D for 500, M for 1000
l Estimation of the outcome of a number operation is useful in checking the answer.

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