Read a graph as a story: rising, falling, steady
Grade 8 Math Worksheet

Circle the best answer.
Ari watches a tank drain. The graph shows liters left against minutes. What are the rate of change and the initial value, and what does each mean?
- The rate is −5 liters each minute, so the tank loses 5 liters a minute; it started with 44 liters.
- The rate is −5 liters each minute, so the tank loses 5 liters a minute; it started with 34 liters.
- The rate is 5 liters each minute, so the tank gains 5 liters a minute; it started with 44 liters.
- The rate is 44 liters each minute, so the tank loses 44 liters a minute; it started with 5 liters.
Bo measures a growing plant. The graph shows centimeters tall against days. What are the rate of change and the initial value, and what does each mean?
Coordinate grid, x from 0 to 7 and y from 0 to 30; segment (3, 19)–(5, 27); Across: days. Up: centimeters tall.. Coordinate grid, x from 0 to 7 and y from 0 to 30; segment (3, 19)–(5, 27); Across: days. Up: centimeters tall.. 1 2 3 4 5 6 7 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 0 Across: days. Up: centimeters tall. - The rate is −4 centimeters each day, so the plant shrinks 4 centimeters a day; it started 7 centimeters tall.
- The rate is 4 centimeters each day, so the plant grows 4 centimeters a day; it started 19 centimeters tall.
- The rate is 7 centimeters each day, so the plant grows 7 centimeters a day; it started 4 centimeters tall.
- The rate is 4 centimeters each day, so the plant grows 4 centimeters a day; it started 7 centimeters tall.
Esme tracks a candle getting shorter. The graph shows millimeters tall against minutes. What are the rate of change and the initial value, and what does each mean?
Coordinate grid, x from 0 to 8 and y from 0 to 32; segment (2, 26)–(6, 18); Across: minutes. Up: millimeters tall.. Coordinate grid, x from 0 to 8 and y from 0 to 32; segment (2, 26)–(6, 18); Across: minutes. Up: millimeters tall.. 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 0 Across: minutes. Up: millimeters tall. - The rate is 2 millimeters each minute, so the candle grows 2 millimeters a minute; it started 30 millimeters tall.
- The rate is −2 millimeters each minute, so the candle shrinks 2 millimeters a minute; it started 30 millimeters tall.
- The rate is 30 millimeters each minute, so the candle shrinks 30 millimeters a minute; it started 2 millimeters tall.
- The rate is −2 millimeters each minute, so the candle shrinks 2 millimeters a minute; it started 26 millimeters tall.
Jun tracks a savings jar. The graph shows dollars saved against weeks. What are the rate of change and the initial value, and what does each mean?
Coordinate grid, x from 0 to 10 and y from 0 to 36; segment (4, 22)–(8, 34); Across: weeks. Up: dollars saved.. Coordinate grid, x from 0 to 10 and y from 0 to 36; segment (4, 22)–(8, 34); Across: weeks. Up: dollars saved.. 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 0 Across: weeks. Up: dollars saved. - The rate is −3 dollars each week, so savings shrink 3 dollars a week; it started with 10 dollars.
- The rate is 3 dollars each week, so savings grow 3 dollars a week; it started with 10 dollars.
- The rate is 22 dollars each week, so savings grow 22 dollars a week; it started with 3 dollars.
- The rate is 3 dollars each week, so savings grow 3 dollars a week; it started with 22 dollars.
Kira studies a graph of bean plant height against time. Is the function linear, and why?
Coordinate grid, x from 0 to 7 and y from 0 to 22; A(1, 5); B(2, 8); C(5, 17); D(6, 20); segment A–B; segment B–C; segment C–D; Across: days. Up: centimeters tall.. Coordinate grid, x from 0 to 7 and y from 0 to 22; A(1, 5); B(2, 8); C(5, 17); D(6, 20); segment A–B; segment B–C; segment C–D; Across: days. Up: centimeters tall.. 1 2 3 4 5 6 7 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 0 A B C D Across: days. Up: centimeters tall. - Not linear: the graph has corners where the pieces meet.
- Not linear: it does not pass through the point (0, 0).
- Linear: each piece rises 3 for each 1 across, so the corners sit on one line.
- Not linear: the pieces have different lengths, so the rate changes.
Luz studies a graph of distance biked against time. Is the function linear, and why?
Coordinate grid, x from 0 to 6 and y from 0 to 22; A(0, 0); B(2, 4); C(4, 12); D(5, 20); segment A–B; segment B–C; segment C–D; Across: hours. Up: kilometers.. Coordinate grid, x from 0 to 6 and y from 0 to 22; A(0, 0); B(2, 4); C(4, 12); D(5, 20); segment A–B; segment B–C; segment C–D; Across: hours. Up: kilometers.. 1 2 3 4 5 6 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 0 A B C D Across: hours. Up: kilometers. - Not linear: the rate is 2 from A to B, 4 from B to C and 8 from C to D.
- Linear: the first and last corners fit a line with rate 4.
- Linear: it starts at the origin, so it is a straight line.
- Linear: the graph rises from left to right.
Milo studies a graph of savings in a jar against time. Is the function linear, and why?
Coordinate grid, x from 0 to 9 and y from 0 to 25; A(1, 9); B(4, 15); C(5, 17); D(8, 23); segment A–B; segment B–C; segment C–D; Across: weeks. Up: dollars.. Coordinate grid, x from 0 to 9 and y from 0 to 25; A(1, 9); B(4, 15); C(5, 17); D(8, 23); segment A–B; segment B–C; segment C–D; Across: weeks. Up: dollars.. 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 0 A B C D Across: weeks. Up: dollars. - Linear: each piece rises 2 for each 1 across, so the corners sit on one line.
- Not linear: the piece from C to D is longer than the piece from A to B.
- Not linear: the line bends at B and at C.
- Not linear: it starts at 9, not at 0.
Pia compares two kites. A's graph is shown. B's table (x | y) is 1 | 9, 3 | 15, 5 | 21. Which statement is right about rates and initial values?
Coordinate grid, x from 0 to 6 and y from 0 to 24; segment (3, 13)–(5, 21) labeled A; Line A is graph A.. Coordinate grid, x from 0 to 6 and y from 0 to 24; segment (3, 13)–(5, 21) labeled A; Line A is graph A.. 1 2 3 4 5 6 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 0 A Line A is graph A. - B has both the greater rate, 6 against 4, and the greater initial value, 6 against 1.
- A has both the greater rate, 4 against 3, and the greater initial value, because its first value, 13, is more than 9.
- A has the greater rate of change, 4 against 3, but B has the greater initial value, 6 against 1.
- B has the greater rate, 6 against 1, but A has the greater initial value, 4 against 3.
Ren compares two plants. B's graph is shown. A's table (x | y) is 1 | 15, 3 | 21, 5 | 27. Which statement is right about rates and initial values?
Coordinate grid, x from 0 to 6 and y from 0 to 30; segment (2, 17)–(4, 27) labeled B; Line B is graph B.. Coordinate grid, x from 0 to 6 and y from 0 to 30; segment (2, 17)–(4, 27) labeled B; Line B is graph B.. 1 2 3 4 5 6 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 0 B Line B is graph B. - B has both the greater rate, 5 against 3, and the greater initial value, because its first value, 17, is more than 15.
- B has the greater rate of change, 5 against 3, but A has the greater initial value, 12 against 7.
- A has both the greater rate, 6 against 5, and the greater initial value, 12 against 7.
- A has the greater rate, 12 against 7, but B has the greater initial value, 5 against 3.
Tala compares two savings jars. A's graph is shown. B's table (x | y) is 2 | 14, 5 | 20, 8 | 26. Which statement is right about rates and initial values?
Coordinate grid, x from 0 to 6 and y from 0 to 28; segment (3, 17)–(5, 25) labeled A; Line A is graph A.. Coordinate grid, x from 0 to 6 and y from 0 to 28; segment (3, 17)–(5, 25) labeled A; Line A is graph A.. 1 2 3 4 5 6 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 0 A Line A is graph A. - B has both the greater rate, 6 against 4, and the greater initial value, 10 against 5.
- B has the greater rate, 10 against 5, but A has the greater initial value, 4 against 2.
- A has the greater rate of change, 4 against 2, but B has the greater initial value, 10 against 5.
- A has both the greater rate, 4 against 2, and the greater initial value, because its first value, 17, is more than 14.

