ADDITIONAL SYSTEM INFORMATION :
Windows 10

A DESCRIPTION OF THE PROBLEM :
BigDecimal rounding does not work as expected during multiplication/division, when provided with MathContext having the precision details.

After multiplication/division, if we set the scale like below, it works as expected
            .setScale(8, BigDecimal.ROUND_HALF_UP)

But if we provide the equivalent scale using MathContext, like below, it does not round it properly, but instead truncates it by 2 decimal places..!
        new MathContext(8, RoundingMode.HALF_UP)

Also, during division, if we directly divide a BigDecimal with another without specifying precision details, we get an exception. (This works with multiplication though)
       BigDecimal quantity = new BigDecimal(178643);
       val1 = quantity.divide(new BigDecimal(1.0394)); // Exception at this point - "java.lang.ArithmeticException: Non-terminating decimal expansion; no exact representable decimal result."
      "java.lang.ArithmeticException: Non-terminating decimal expansion; no exact representable decimal result."

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
// Multiplication -- using setScale
        BigDecimal quantity = new BigDecimal(178643);
        BigDecimal val1 = quantity.multiply(new BigDecimal(1.0394)).setScale(8, BigDecimal.ROUND_HALF_UP);
        // Multiplication -- precision by using MathContext.
        BigDecimal val2 = quantity.multiply(new BigDecimal(1.0394), new MathContext(8, RoundingMode.HALF_UP));
        System.out.println("After multiplication, with normal rounding, val1 =" + val1
                + ", rounding using math context, val2=" + val2);
        // Division -- using setScale -- This produces an error:
            // "java.lang.ArithmeticException: Non-terminating decimal expansion; no exact representable decimal result."
        // val1 = quantity.divide(new BigDecimal(1.0394)).setScale(8, BigDecimal.ROUND_HALF_UP);
        // Division -- passing the scale and rounding mode - works fine.
        val1 = quantity.divide(new BigDecimal(1.0394), 8, RoundingMode.HALF_UP);
        // Division -- precision by using MathContext.
        val2 = quantity.divide(new BigDecimal(1.0394), new MathContext(8, RoundingMode.HALF_UP));
        System.out.println("After division, with normal rounding, val1 =" + val1 + ", rounding using math context, val2=" + val2);

Try the above code in a simple java program

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
185681.53420000 (in case of multiplication)
171871.27188763 (in case of division)
ACTUAL -
185681.53 (in case of multiplication)
171871.27 (in case of division)

---------- BEGIN SOURCE ----------
import java.math.BigDecimal;
import java.math.MathContext;
import java.math.RoundingMode;

public class MathContextIssues {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        // Multiplication -- using setScale
        BigDecimal quantity = new BigDecimal(178643);
        BigDecimal val1 = quantity.multiply(new BigDecimal(1.0394)).setScale(8, BigDecimal.ROUND_HALF_UP);
        // Multiplication -- precision by using MathContext.
        BigDecimal val2 = quantity.multiply(new BigDecimal(1.0394), new MathContext(8, RoundingMode.HALF_UP));
        System.out.println("After multiplication, with normal rounding, val1 =" + val1
                + ", rounding using math context, val2=" + val2);
        // Division -- using setScale -- This produces an error:
        // "java.lang.ArithmeticException: Non-terminating decimal expansion; no exact
        // representable decimal result."
        // val1 = quantity.divide(new BigDecimal(1.0394)).setScale(8,
        // BigDecimal.ROUND_HALF_UP);
        // Division -- passing the scale and rounding mode - works fine.
        val1 = quantity.divide(new BigDecimal(1.0394), 8, RoundingMode.HALF_UP);
        // Division -- precision by using MathContext.
        val2 = quantity.divide(new BigDecimal(1.0394), new MathContext(8, RoundingMode.HALF_UP));
        System.out.println(
                "After division, with normal rounding, val1 =" + val1 + ", rounding using math context, val2=" + val2);
    }
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
.setScale(8, BigDecimal.ROUND_HALF_UP) // for multiplication
.divide(new BigDecimal(1.0394), 8, RoundingMode.HALF_UP); // for division

FREQUENCY : always