This is documentation for Mathematica 8, which was
based on an earlier version of the Wolfram Language.
View current documentation (Version 11.1)

Typing Matrices

Creating a New Matrix

Choose InsertTable/MatrixNew. Use the dialog box that pops up to create a matrix.
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Filling in Placeholders in a Matrix

Suppose the entry in the top-left position is selected.
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Type an entry and select the next placeholder with the Tab key; repeat. (Use Shift+Tab to go backward.)
Type , press Tab.
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Type , press Tab.
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Type , press Tab.
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Press the Control key and the Space bar at the same time to get out of the grid.
Type , press Ctrl+Space.
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Move the insertion point to get out of the matrix.
Press RightArrow.
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Adding a New Column in a Matrix

Place the insertion point to the right of any entry; here the insertion point is to the right of the entry at the top left.
Place the insertion point.
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Press the Control and Comma keys at the same time. A column of placeholders will appear, with the top one selected.
Press Ctrl+Comma.
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Adding a New Row in a Matrix

Place the insertion point to the right of any entry; here the insertion point is to the right of the entry at the top left.
Place the insertion point.
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Press the Control and Enter keys at the same time. A row of placeholders will appear, with the first one selected.
Press Ctrl+Enter.
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