cost function calculator
1)durable plastic key. 2)ECO-Friendly 3)big screen 4)auto-power-off.
description
check and correct electronic calculator Autumn Festival
1)12 digits and correct calculator.
2)the check key and correct key can modify the wrong inputted numbers.
3)dual power supply ( solar and battery).
4)99 steps reply to check each process. and it can correct the mis-input .
5)it switch the power off automatially if there has been no key entered for about 5 minutes.
6)it seems clearly with big screen.
7)magnet on the back.
cost function calculator