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Vectors · SumNinja
Add two-dimensional vectors by combining their horizontal and vertical parts.
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Add the two moves. Where do you end up?
Add top to top, then bottom to bottom.
Choose an answer when you’re ready.
Add the top numbers: 2 + (−1) = 1. Add the bottom numbers: 1 + 3 = 4.
A vector describes a move with both size and direction. In a column vector, the top number gives the horizontal move. The bottom number gives the vertical move. Positive numbers move right or up; negative numbers move left or down.
Suppose one move takes you 2 steps right and 1 up. A second move takes you 1 left and 3 up. Together, they take you 1 right and 4 up. Add the top numbers, then add the bottom numbers.
(2, 1) + (−1, 3) = (1, 4)
Horizontal: 2 + (−1) = 1. Vertical: 1 + 3 = 4. Keep the two parts in the same order.
3 × (2, −1) = (6, −3)
Scaling repeats the whole move. Multiply both parts by 3: six steps right and three down.
The first button starts with addition. The lessons below also show how to subtract or scale vectors, find a move between points, measure length, and use a dot product. Their practice links let you try each skill. These activities use 2D vectors.