KCalc version 17.04.0, with KDE Frameworks 5.32.0 and Qt 5.7.1.

If you enter a number with the keyboard or application buttons, the Exponent (x*10y) button works appropriately; example:

1. Enter 2 in KCalc
2. Press x*10y button
3. Observer 2e0 in display

However, if the current number was not entered immediately previously, it is "lost" (treated as zero).

Issue #1: Pasted value

1. Copy single character 2 to clipboard
2. Paste into KCalc
3. Press x*10y button
4. Observe result is 0e0, *NOT* 2e0, as expected

Issue #2: Result of prior calculation (perhaps arguable, as other calculators treat this case in different ways)

1. Add 1 and 1
2. Observe result is 2
3. Press x*10y button
4. Observe result is 0e0, *NOT* 2e0, as expected