A display input apparatus comprising: a display portion that displays a numerical value input screen for accepting an input of a numerical value and displays an input numerical value, namely, a numerical value that is input, on a rectangular numerical value display region of the numerical value input screen, the rectangular numerical value display region being long in a left-right direction, a touch panel portion that is disposed correspondingly to the display portion and accepts a touch operation on a screen of the display portion, and a control portion that detects, based on an output from the touch panel portion, the touch operation accepted by the touch panel portion, wherein when the touch panel portion accepts a region dividing operation as a touch operation that divides the numerical value display region in the numerical value input screen along a second direction that meets a first direction at right angles, the control portion sets a line, which passes through a predetermined position of the numerical value display region in the second direction, as a first reference line; sets an end edge of the rectangular shape, which is opposite to the first reference line of the numerical value display region in the first direction, as a second reference line; obtains a ratio for input numerical value calculation that is a ratio of a distance from the first reference line to the second reference line and a distance from the first reference line to a division line of the numerical value display region that is divided by the region dividing operation; and obtains a numerical value, which is obtained by multiplying a maximum value or minimum value in a numerical value input range of the numerical value input screen by the ratio for input numerical value calculation, as the input numerical value, and the display portion displays the input numerical value, which is obtained by the control portion, in the numerical value input screen, characterized in that - said region dividing operation is a touch operation in which a touch position slides in a slide direction which deviates from a vertical direction of the numerical value display region, to divide the numerical value display region, where the input numerical value is displayed, and - the control portion sets beforehand an intermediate line that extends along the first direction between upper and lower edges of the rectangular numerical value display region that is long in the left-right direction, and identifies a line, which passes, in the vertical direction, through an intersection between the intermediate line and a line along the slide direction in the region dividing operation, as the division line. a display portion that displays a numerical value input screen for accepting an input of a numerical value and displays an input numerical value, namely, a numerical value that is input, on a rectangular numerical value display region of the numerical value input screen, the rectangular numerical value display region being long in a left-right direction, a touch panel portion that is disposed correspondingly to the display portion and accepts a touch operation on a screen of the display portion, and a control portion that detects, based on an output from the touch panel portion, the touch operation accepted by the touch panel portion, wherein when the touch panel portion accepts a region dividing operation as a touch operation that divides the numerical value display region in the numerical value input screen along a second direction that meets a first direction at right angles, the control portion sets a line, which passes through a predetermined position of the numerical value display region in the second direction, as a first reference line; sets an end edge of the rectangular shape, which is opposite to the first reference line of the numerical value display region in the first direction, as a second reference line; obtains a ratio for input numerical value calculation that is a ratio of a distance from the first reference line to the second reference line and a distance from the first reference line to a division line of the numerical value display region that is divided by the region dividing operation; and obtains a numerical value, which is obtained by multiplying a maximum value or minimum value in a numerical value input range of the numerical value input screen by the ratio for input numerical value calculation, as the input numerical value, and the display portion displays the input numerical value, which is obtained by the control portion, in the numerical value input screen, - said region dividing operation is a touch operation in which a touch position slides in a slide direction which deviates from a vertical direction of the numerical value display region, to divide the numerical value display region, where the input numerical value is displayed, and - the control portion sets beforehand an intermediate line that extends along the first direction between upper and lower edges of the rectangular numerical value display region that is long in the left-right direction, and identifies a line, which passes, in the vertical direction, through an intersection between the intermediate line and a line along the slide direction in the region dividing operation, as the division line.