Multiplication and Imperial unit

Key Operations Display
Key Operation 88888888' 88"8
510 8888888 5' 10"8
[foot] 88888510' 88" 8
11 888885 10' 1 1"8
[Inch] 888885 10' 1 1"8
4 888885 10' 1 1"4
Key Operation 888885 10' 1 1"4                              (Not necessary to press dori Button as third parameter will be treated as dori by default )
[X] 888885 10' 1 1"4
27 88888888' 27" 8
[Foot] 88888827' 88"8
4 88888827' 84" 8
[Inch] 88888827' 84" 8
3 88888827' 84"3
Key Operation 88888827' 84" 3                              (Not necessary to press dori Button as third parameter will be treated as dori by default )
Answer-   SQFEET
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