The algorithm ADDN implements N-bit fixed-width binary addition for non-negative integers and ignores overflows. For example, ADD4((1101)2,(1100)2) = (1001)2 because (1101)2 + (1100)2 = (11001)2 but the leading bit can’t fit in the 4-bit register. A standard way for computers to represent negative integers is the "two’s complement" method TN (x). Non-negative integers from 0 to 2N−1 − 1 are represented using ordinary fixed-width binary (e. g. T4(3) = (0011)2), and a negative integer n with −2 N−1 ≤ n is represented using the binary expansion of the (positive) integer 2N + n (e. g. T4(−3) = (1101)2 because 24 + (−3) = 13 = (1101)2). This representation allows us to use ADDN unchanged for both positive and negative integers! To partially prove this claim, show that if a and b are negative integers with −2 N−1 ≤ a + b, then ADDN (TN (a), TN (b)) = TN (a + b). (Hint: In what situation does ADDN (x, y) not equal x + y, and then what does it equal instead?)

Formatting rows and columns is similar to cell formatting. in an openoffice calc spreadsheet, you can format data entered into rows and columns with the of the rows and columns options. you can insert rows and columns into, or delete rows and columns from, a spreadsheet. use the insert or delete rows and columns option on the insert tab. alternatively, select the row or column where you want new rows or columns to appear, right-click, and select insert only row or only column options. you can hide or show rows and columns in a spreadsheet. use the hide or show option on the format tab. for example, to hide a row, first select the row, then choose the insert tab, then select the row option, and then select hide. alternatively, you can select the row or columns, right-click, and select the hide or show option. you can adjust the height of rows and width of columns. select row and then select the height option on the format tab. similarly, select column, then select the width option on the format tab. alternatively, you can hold the mouse on the row and column divider, and drag the double arrow to the position. you can also use the autofit option on the table tab to resize rows and columns.