Page 10 - SM Class 5 Inner.cdr

Comparing Indian and international system of numeration

Upto ten thousands, both system follow the same place value names. However,

after ten thousands the names change.

Note

Indian system International system
1 lakh = 100 thousands
10 lakh = 1 Million
1 crore = 10 Million
10 crores = 100 Millions
100 crores = 1 billion

E xercise 1.2

1. Write these numbers in figure :
a. Two million eighty-four thousand seven hundred and seventy-seven.

b. Eighty-three million five hundred and twenty-nine thousand one
hundred and one.

c. Six billion nine million fifty thousand three hundred and ninety-two.

2. Write the number name of the following in international system :
a. 437941 b. 701286 c. 5325844

d. 8064200 e. 36500000 f. 9540458
g. 57235471 h. 2050060000

Rounding Numbers

Rounding means making a number simpler but keeping its value close to what
it was. We can round off a number to nearest 10, 100 or 1000.

Rule for rounding to the nearest 10

Look at the number in the one’s place
For 0, 1, 2, 3, or 4 we round down.

For 5, 6, 7, 8, or 9 we round up.

To round numbers to the nearest tens make the numbers that end in 1 through
4 into the next lower number that ends in 0. For example 2546374 rounded to
the nearest ten would be 2546370.

Numbers that end in a digit of 5 or more should be rounded up to the next even
ten. The number 2548788 rounded to the nearest ten would be 2548790.

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Mathematics In Focus - 5