Using digits 1-7 round to 6,300,000

Mathematics rule of rounding a number. Let’s create a 7 digit number composed of 1-7 digits to be rounded to 6,300,000. Let's have 6,312,457 in where:  7=ones, 5=tens, 4=hundreds, 2= thousands, 1= ten thousands, 3= hundred thousands, 6 = millions.       Another rule in rounding off numbers. Any number less than 5, round down. Any number more than 5, round up.                                                                                Therefore: 6,312,457 will be rounded to  6,300,000.