## 1. Summary

- 1 metre = 100 centimetres
- 1 kilogram = 1,000 grams
- 1 kilometre = 1000 metres
- 1 litre = 1,000 millilitres

**Ascending order:**

The arrangement of numbers from the smallest to the greatest is called ascending order.

e.g. 2789, 3560, 4567, 7662, 7665

**Descending order:**

The arrangement of numbers from the greatest to the smallest is called descending order.

e.g. 7665, 7662, 4567, 3560, 2789

If two numbers have an unequal number of digits, then the number with the greater number of digits is greater. If two numbers have equal number of digits then, the number with greater valued digit on the extreme left is greater. If the digits on extreme left of the numbers are equal then the digits to the right of the extreme left digits are compared and so on.

The greatest single-digit number is 9. When we add 1 to this single-digit number, we get 10, which is the smallest two-digit number. Therefore, the greatest single-digit number + 1 = the smallest two-digit number.

The greatest two digit-number is 99. When we add 1 to this two-digit number, we get 100, which is the smallest three-digit number. Therefore, the greatest two-digit number + 1 = the smallest three-digit number.

The greatest three-digit number is 999. When we add 1 to this three-digit number, we get 1000, which is the smallest four-digit number. Therefore, the greatest three-digit number + 1 = the smallest four-digit number.

The greatest four-digit number is 9999. When we add 1 to this four-digit number, we get 10,000, which is the smallest five-digit number. Therefore, the greatest four-digit number + 1 = the smallest five-digit number.

The greatest five-digit number is 99999. When we add 1 to this five-digit number, we get 1,00,000, which is the smallest six digit number. Therefore, the greatest five-digit number + 1 = the smallest six-digit number. The number, that is, one with five zeroes (100000), is called one lakh.

The greatest six-digit number is 999999. When we add 1 to this six-digit number, we get 10,00,000, which is the smallest seven-digit number. Therefore, the greatest six-digit number + 1 = the smallest seven-digit number. The number, that is, one with six zeroes (1000000), is called ten lakh.

The greatest seven-digit number is 9999999. When we add 1 to this seven-digit number, we get 10000000, which is the smallest eight-digit number. Therefore, the greatest seven-digit number + 1 = the smallest eight-digit number.The number, that is, one with seven zeroes (10000000),is called one crore.

Commas are placed to the numbers to help us read and write large numbers easily.

**Commas in Indian numeration system:**

As per Indian numeration, the first comma is placed after the hundreds place. Commas are then placed after every two digits.

e.g. (i) 88,76,547

The number can be read as eighty-eight lakh seventy-six thousand five hundred and forty-seven.

(ii) 5, 67, 89, 056

The number can be read as five crore sixty-seven lakh eighty-nine thousand and fifty-six.

The following place value chart can be used to identify the digit in any place in the Indian system.

Crores |
Lakhs |
Thousands |
Ones |
|||||

Tens |
Ones |
Tens |
Ones |
Tens |
Ones |
Hundreds |
Tens |
Ones |

**Commas in International system:**

As per International numeration system, the first comma is placed after the hundreds place. Commas are then placed after every three digits.

e.g. (i) 8,876,547

The number can be read as eight million eight hundred seventy-six thousand five hundred and forty-seven.

(ii) 56,789, 056

The number can be read as fifty-six million seven hundred eighty-nine thousand and fifty-six.

Use the following place value chart to identify the digit in any place in the International system.

Billions |
Millions |
Thousands |
Ones |
||||||||

Hundreds |
Tens |
Ones |
Hundreds |
Tens |
Ones |
Hundreds |
Tens |
Ones |
Hundreds |
Tens |
Ones |

Comparison of the Indian and the international numeration systems:

Indian Numeration |
Crore |
Ten Lakh |
Lakh |
Ten Thousand |
Thousand |
Hundred |
Tens |
Ones |

Numbers |
10000000 |
1000000 |
100000 |
10000 |
1000 |
100 |
10 |
0 |

International Numeration |
Ten Million |
Million |
Hundred |
Ten Thousand |
Thousand |
Hundred |
Tens |
Ones |

**Units of measurement:**