Linear, proportional or neither?
Grade 8 Math Worksheet
Circle the best answer, or write your answer on the line.
Read this first
Use the table
input: hours after lighting output: height in cm 4 12 1 18 3 14 6 8 Kira measures a candle at a few hours after it is lit. Is the table linear, proportional or neither?
- Linear, not proportional: every rate is -2, but input 0 gives 20
- Neither: the outputs jump -4, -2 and -4
- Proportional: every rate is -2, so the line is straight
In math club, Luz gets a table with the rows mixed up. Is it linear, proportional or neither?
- Linear, not proportional: every rate is 3, but input 0 gives -7
- Proportional: every rate is 3, so the line is straight
- Neither: the outputs jump 3, 6 and 6
Pia plots four points from a rule card in math club. Is the graph linear, proportional or neither?
- Neither: some outputs are negative, so a straight line cannot fit them
- Linear, not proportional: every rate is 3, but input 0 gives -1
- Proportional: every rate is 3, so the line is straight
Ren plots four points from a rule card, but none of them is on the up axis. Is the graph linear, proportional or neither?
- Proportional: every rate is -2, and input 0 gives 0
- Linear, not proportional: every rate is -2, but no point has input 0
- Neither: the points go down, not up
Zee fills in x = 0, 1, 2 and 3 for the rule y = -3x + 2. Is it linear, proportional or neither?
- Linear, not proportional: every rate is -3, but input 0 gives 2
- Proportional: every rate is -3, so the line is straight
- Neither: the outputs go down
Ari fills in x = 0, 1, 2 and 3 for the rule y = x × x + 1. Is it linear, proportional or neither?
- Proportional: y grows when x grows
- Linear, not proportional: the rate is 1, and input 0 gives 1
- Neither: the rates are 1, 3 and 5
Kira's bath has 30 liters of water in it, and the circle adds 12 liters each minute. Input: minutes. Output: liters. Is it linear, proportional or neither?
- Proportional: 12 more liters every minute, so the line is straight
- Linear, not proportional: 12 liters each minute, but it is 30 liters at minute 0
- Neither: the tub will overflow
Luz builds solid cubes from toy blocks. Edges of 1, 2 and 3 blocks need 1, 8 and 27 blocks. Input: edge. Output: blocks. Is it linear, proportional or neither?
- Neither: the blocks go up by 7, then 19
- Linear, not proportional: every cube has 6 faces
- Proportional: an edge of 0 blocks needs 0 blocks, and the count grows
Use the table
input: week output: height in cm 1 5 2 8 3 11 4 15 5 17 Rows sorted by input.
Milo copied a plant log, and one row has a copying slip. All the other rows are on one line. Which input's row is off the line?
Pia checks a rule table that should be linear. One row is wrong. Which input's row is off the line?
