# Knowing Our Numbers – Chapter 1/Indian & International System of Numeration.

**CBSE Class 6 Mathematics/Knowing our numbers – Chapter 1**

**Indian and International System of Numeration:**

**Use of commas:**

**Indian System of Numeration:**

In Indian system of numeration we use ones, tens, hundreds, thousands and then lakhs and crores. Commas are used to mark thousands, lakhs and crores. The first comma comes after hundreds place (three digits from right). The second comes two digits later (five digits from the right). The third comma comes after another two digits (seven digits from the right).

For example, 5, 08, 01,592.

Number name of this number is Five crore eight lakh one thousand five hundred ninety two.

**International System of Numeration:**

In International system of numeration commas are used to mark thousands and millions. It comes after every three digits from the right. The first comma marks thousands and the next comma marks millions.

For example, 50,801,592.

Number name of this number in International system are Fifty million eight hundred one thousand five hundred ninety two.

**Answer the following questions:**

**1. Place commas correctly and write the numerals:**

a) Eight crore fifty five lakh three thousand two hundred two.

b) Twenty three lakh four thousand two hundred three.

c) Three million eight hundred twenty three thousand three hundred seventy two.

d) Fifty five million three hundred twenty two thousand eight hundred ten.

**2. Insert commas suitably and write the names according to Indian System of Numeration:**

a) 90875421

b) 42890750

**3. Insert commas suitably and write the names according to International System of Numeration:**

a) 9976543

b) 87965032

**ANSWERS:**

1. a) 8,55,03,202

b) 23, 04,203

c) 3,823,372

d) 55,322,810

2. a) 9,08,75,421 – Nine crore eight lakh seventy five thousand four hundred twenty one.

b) 4, 28, 90,750 – Four crore twenty eight lakh ninety thousand seven hundred fifty.

3. a) 9,976,543 – Nine million nine hundred seventy six thousand five hundred forty three.

b) 87,965,032 – Eighty seven million nine hundred sixty five thousand thirty two.