12.57 * 4.11 = 51.66
1257 *remove the decimal and treat the numbers as whole numbers.
x 411
1257 * 1 x 1257
12570 *10 x 1257
2800 *400 x 7
20000 *400 x 50
80000 *400 x 200
+ 400000 *400 x 1000
516627
516627 is the product of 12.57 and 4.11 without their decimal points.
516627. the decimal point must be moved 4 places because the total count of numbers after the decimal is 4.
from 516627 to 51.6627 ; round to the nearest hundredth 51.66