RBI sir Welcomes to study,Maths chapter ,Rounding off ,its other names are Approximation ,Estimation ,Nearest Value , its means ,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 ,by single curved sign , like ~ and other by using double curved line single curved line,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 smaller periods will be zero, But Digits is in the group of five,six,seven,eight,nine then Rounding up and added one and all smaller number will be zero,Special notes from RBI Sir,some types of Rounding the numbers ,Type one,nearest to whole ,type two ,nearest to periods on natural and Decimal fractions,type three n,fraction,surds rounding etc ,type 4,smaller to greater rounding Main concept 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,Attention, right sided digit or number is smaller than left sided number of integers and decimal,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:RBI Sir