RBSE Class 6 Maths Notes Chapter 1 Knowing Our Numbers

These comprehensive RBSE Class 6 Maths Notes Chapter 1 Knowing Our Numbers will give a brief overview of all the concepts.

RBSE Class 6 Maths Chapter 1 Notes Knowing Our Numbers

→ Numbers can be represented by numerals.

→ Numbers help us to count the different objects. 

→ Between two numbers, the number which has more digits is greater. If number of digits is same in the both, then we compare the first digit on the left of both numbers. In which number this digit is greater, that will be the greater number. If this digit is also same then we compare further digits from left to right.

→ We use the above method to arrange the numbers in ascending or descending order.

→ Ascending means increasing order, i.e., arrange from smallest number to largest number.

→ Descending means decreasing order, i.e., arrange from largest number to smallest number.

→ While forming of a greatest number, we write digits in descending order from left to right and for smallest number we write digits in ascending order from left.

→ The smallest four digit number is 1000, therefore the largest three digit number is 999. The smallest five digit number is 10000, therefore the largest four digit number is 9999. The smallest six digit number is 1,00,000 (one lakh), therefore the largest five digit number is 99,999. The same rule is followed for large numbers.

→ Use of commas helps in writing and reading numbers. In Indian statics, first comma is used after the third digit from right, then others after the gap of two-two digits. Comma will separate thousand, lakh and crore.

→ In international method of statics, comma is used after every three digits from the right. After three and six digits, comma will separate thousand and million respectively.

→ In Indian system of numeration, the first digit from right is representing unit, seamd is ten, third is hundred, fourth is thousand, fifth is ten thousand and sixth digit is

• 10 Lakhs = 1 Million
• 10 Millions = 1 Crore
• 1 Billion = 1,000 Million
• 1 Trillion = 1,000 Billion

→ Measurement of Lengths

• 10 Millimeter = 1 centimeter (1 cm)
• 1 Metre = 100 centimeter = 1000 millimeter
• 1 Kiliometre = 1000 meter

→ Measurement of Weights :

• 1 Kilogram = 1000 gram
• 1 Gram = 1000 milligram
• 1 Litre = 1000 millilitre

→ Several times we do not need to exact numbers, only estimated numbers are enough. For examples 5119 is closer to 5000 in thousand and closer to 5100 in hundred, which depends upon requirement.

→ Rounding Numbers to the nearest tens : Numbers 1,2,3,4 are closer to the number 0, as compared to number 10. Hence we round them off to number 0. And 6, 7, 8, 9 are doser to the number 10, so we round off them to number 10.

→ Rounding Numbers to the nearest hundreds : Numbers 1 to 49 are doser to 00 and 50 to 99 are doser to 100.

→ Rounding Numbers to the nearest thousand: Numbers 1 to 499 are closer to 000 and 500 to 999 are closer to 1000.

→ When we are to use many operations in a single problem, then we have to follow the certain order. We use the brackets to write statements in explidt form.

• ( ) = common bracket
• { } = curly brackets
• [ ] = square brackets

→ Many numeral system are being used in different parts of the world. But these days, we use only Hindu-Arabic numerals system in all over the world. One more numeral system is used at some parts of the world. This is called Roman Numerals.

→ Some Roman Numerals are given below :