Abstract: A calculation apparatus in which a controlling unit performs a first storing process for storing a first value in a storing unit; a first displaying process for executing operation on a second value, using the first value to obtain and display a first and second output value on a displaying unit; a second displaying process for executing operation on a third value, using the first value to obtain and display a third and fourth output value on the displaying unit; a second storing process for adding the third output value to the first output value and the fourth output value to the second output value to obtain and store a first sum and a second sum in the storing unit; and a sum displaying process for displaying the first and second sum stored in the storing unit on the displaying unit in response to operation of the key unit.

Abstract: An electronic device includes a casing having an opening; a circuit board having a plurality of electrodes, which is provided inside the casing; a contact member having a plurality of contact points corresponding to the electrodes, which is provided so as to seal the opening; and a key unit (press-key unit) having a key operation unit corresponding to the contact points, which is provided to the opening. The key unit (press-key unit) is attached to the opening detachably.

Abstract: A calculation apparatus in which a controlling unit performs a first storing process for storing a first value in a storing unit; a first displaying process for executing operation on a second value, using the first value to obtain and display a first and second output value on a displaying unit; a second displaying process for executing operation on a third value, using the first value to obtain and display a third and fourth output value on the displaying unit; a second storing process for adding the third output value to the first output value and the fourth output value to the second output value to obtain and store a first sum and a second sum in the storing unit; and a sum displaying process for displaying the first and second sum stored in the storing unit on the displaying unit in response to operation of the key unit.

Abstract: A cover mechanism includes a cover which is detachably attached to a housing and a slide member which is slidably attached to the housing. The slide member includes a lock portion which locks the cover to keep the cover closed and a push-up portion which pushes up the cover as the slide member slides in a direction to release the lock.

Abstract: An electronic device includes a casing having an opening; a circuit board having a plurality of electrodes, which is provided inside the casing; a contact member having a plurality of contact points corresponding to the electrodes, which is provided so as to seal the opening; and a key unit (press-key unit) having a key operation unit corresponding to the contact points, which is provided to the opening. The key unit (press-key unit) is attached to the opening detachably.

Abstract: A cover mechanism includes a cover which is detachably attached to a housing and a slide member which is slidably attached to the housing. The slide member includes a lock portion which locks the cover to keep the cover closed and a push-up portion which pushes up the cover as the slide member slides in a direction to release the lock.

Abstract: A key device includes: a chassis which has an opening divided by one of a vertical rib and a horizontal rib; a plurality of keys which are arranged along the opening; and a substrate which is housed in the chassis, wherein the rib is engaged with the substrate.

Abstract: A key device includes: a chassis which has an opening divided by one of a vertical rib and a horizontal rib; a plurality of keys which are arranged along the opening; and a substrate which is housed in the chassis, wherein the rib is engaged with the substrate.