We name points with coordinates and begin ratio and proportion.
Coordinates
A point is written as (x, y): the first number is how far across (x), the second is how far up (y). So (4, 3) is 4 across and 3 up.
Ratio and proportion
A ratio compares amounts, like 2 : 3. In proportion, amounts grow together: if 1 cake needs 2 cups of flour, 3 cakes need 6 cups.
Remember
- Coordinates: (across, up) = (x, y).
- Proportion: quantities grow at the same rate.