change a percentage cell value but the value in the formula bar doesn't change accordingly

Steps to Reproduce

1. load the attached file, B6 is 10% at this moment
2. enter 1 at B6, a cell with percentage value
3. select B6, check the value in the formula bar

Current Result

it shows 10%, the original value, instead of the new value 1%

Expected Result

1%

Debug Information

1. this bug only happens on percentage value, not happen on string, date, number with currency.

Workaround

keikai-470.js