RBI sir Welcomes to learn ,Maths chapter ,Rounding off ,its synonyms are ,Approximation ,Estimation ,Nearest Value , Definition of Round off ,finding the place value of digits or number according to round up and round down ,We write estimation sign by using the both ways ,first sign if estimation is ~ and other is its double format or single curved line ,curved equal signs,Rounding down rule from RBI Sir,If the just smaller digit to the rounding number is in the group of zero,one,two ,three,four then No added the number Rounding and next all zero, But Digits is in the group of five,six,seven,eight,nine then Rounding digit takes one ,one is added and all smaller number will be zero,Special notes from RBI Sir,some types of Rounding the numbers ,Nearest to whole and periods of the Natural numbers,and other Nearest to whole and periods of Decimal fractions,And rounding the fraction and surds etc ,Main concept or steps to round off the numbers from RBI Sir,Step one ,Set the number or write the number into standard form or into question format ,for example Rounding the number 8 Nearest to whole then,firstly write the number eight into decimal form to get all smaller periods than Rounding digit,here let zero, and in decimal fraction for Rounding Nearest to whole ,we see the digit that lies just after decimal,Special notes from RBI Sir,Always right sided digit or number is smaller into decimal or into integers,Some stuff question may be like Smaller number to bigger Rounding,for example round off the number nine nearest to thousand,here one verses thousand so set number into three digits or into thousand the number nine by putting or let zeros ,then Applied Roundind up and down rules ,or Number line Method or Place value Method,Trick from RBI Sir,Rounding down digits zero ,one,two,three,four says us ni change all zeros But Rounding up digits are five ,six,seven,eight,nine says us added one and all zero for all smaller than Rounding periods,For the fraction rounding ,first change the fraction into mix fraction then compare ,if fraction part is less than five then no added one,thanks