Learning Targets

Standards: CCSS 6.NS.C.5–8 Time: ~45 min Materials: This activity (device or printed), scratch paper Grade 6
Teacher Notes (not printed)

Pacing

  • Launch (5 min): Read "The Brief." Anchor the map scale: "1 grid square = 1 city block, and (0, 0) is City Hall." Model naming one landmark by reading across (x) then up/down (y).
  • Design work (30–35 min): Students complete Task 1 → 5 in order. Task 5 (Sign-off) summarizes the plan; Tasks 2–4 can be checked as they go.
  • Debrief (5–10 min): Discuss why subway distance uses absolute value, and how a reflection across an axis flips exactly one sign.

Differentiation

  • Level 1 (support): Use the green callouts and bilingual (EN/ES) prompts. Provide a printed four-quadrant grid. Encourage "right/left first, then up/down" finger tracing.
  • Level 2 (enrichment): Have students justify the elevation ordering with a number line, generalize the reflection rule in words, and find a route distance that requires two same-line segments (an L-shaped subway path).

STEM Connection

  • This is an authentic GIS / urban-planning task: city planners, surveyors, and transit engineers locate everything on a coordinate grid (like latitude/longitude or a city block grid), record elevations as signed numbers, and compute straight-line block distances with coordinates — exactly the workflow students use here.
Unit 9 · Math Architect · Integers & the Coordinate Plane (6.NS.C.5–8)

Design Challenge: City Grid Engineer

You are the lead planner for Gridport, a new smart city. Every street, park, and station is mapped on a four-quadrant coordinate grid centered on City Hall at (0, 0). Use coordinates, integers, absolute value, distance, and reflections to lay out the city, log elevations, route the subway, and mirror a matching district — then sign off your master plan.

Standard 6.NS.C.5–8 Four Quadrants Absolute Value Distance on the Plane Reflections
1 · LocateName landmark coordinates in all 4 quadrants.
2 · RankOrder elevations & use absolute value.
3 · RouteMeasure subway distance with coordinates.
4 · MirrorReflect a district across an axis.
5 · Sign offSummarize the master plan.
Plan checks approved: 0 / 11

The Brief

The city engineering office handed you the official Gridport site map. Read every coordinate the same way:

MAP RULE  (x, y) = (blocks right/left, blocks up/down) from City Hall (0, 0)  ·  1 grid square = 1 city block

Deliverable 1
Name & plot landmark coordinates across all four quadrants.
Deliverable 2
Order elevations and route the subway with distance + absolute value.
Deliverable 3
Reflect the matching district and sign off the master plan.
Level 1 · Support

A coordinate (x, y) tells you two moves from the center. The x tells you right (+) or left (−). The y tells you up (+) or down (−). Always do the x-move first, then the y-move.

Español: Una coordenada (x, y) da dos movimientos desde el centro. La x va a la derecha (+) o izquierda (−). La y va arriba (+) o abajo (−). Muévete primero en x, luego en y.

Task 1 · Locate the Landmarks Four quadrants

Four key landmarks are already marked on the city map. Read each point's coordinates straight off the grid and record them. Watch the signs in each quadrant.

x y I II III IV 2 4 6 -2 -4 2 4 -2 -4 Park Quadrant II Station Quad I Stadium Quad IV Market Quad III
Gridport official site map1 square = 1 block

Q1.1 — Coordinates of Green Park

( , )

Q1.2 — Coordinates of Gold Stadium

( , )

Q1.3 — Pink Market is at (−3, −6). Which quadrant is it in? (Type the number: 1, 2, 3, or 4.)

Level 1 · Support

Find each point by counting from the center. Right is +x, left is −x. Up is +y, down is −y. Quadrants are numbered counter-clockwise starting from the top-right: I (+,+), II (−,+), III (−,−), IV (+,−).

Español: Cuenta desde el centro. Derecha = +x, izquierda = −x, arriba = +y, abajo = −y. Cuadrantes: I (+,+), II (−,+), III (−,−), IV (+,−).

Task 2 · Elevation Survey Compare · order · |absolute value|

Your survey crew logged the elevation of four sites in meters, where 0 = sea level. Positive means above sea level; negative means below. Read the number line, then order them and use absolute value.

Docks −6 Harbor −2 Plaza +1 Reservoir +5
Elevation survey · 0 = sea levelmeters
Site Elevation (m)
Riverside Docks −6
Old Harbor −2
City Hall Plaza +1
Hilltop Reservoir +5
Level 1 · Support

On a number line, left is less and right is more. So −6 < −2 < 1 < 5. Absolute value |n| is the distance from 0 — it is never negative. |−6| = 6 because the Docks are 6 meters from sea level.

Español: En la recta numérica, izquierda = menor, derecha = mayor. El valor absoluto |n| es la distancia desde 0 y nunca es negativo. |−6| = 6.

Q2.1 — Which site has the lowest elevation? Type its elevation number (with sign).

m

Q2.2 — The Docks sit at −6 m. How far is that from sea level? Find |−6|.

m

Q2.3 — A diver says "the Docks are deeper below sea level than the Harbor." Compare distances: |−6| ___ |−2|. Type the symbol >, <, or =.

Level 2 · Enrichment

Careful: −6 is less than −2 (it is colder / lower), but |−6| is greater than |−2| (it is farther from sea level). In one sentence, explain how a number can be smaller yet have a larger absolute value.

Task 3 · Route the Subway Distance on the plane

The new subway runs in straight blocks. Find how many blocks long each straight segment is by using the coordinates — when two stops share an x- or a y-value, the distance is the absolute value of the difference of the other coordinates.

x y 2 6 -4 4 -3 North (−4, 6) East (5, 6) South (5, −3)
Subway plan · straight-block segments1 square = 1 block

Q3.1 — North (−4, 6) → East (5, 6). Same y, so distance = |5 − (−4)|. How many blocks?

blocks

Q3.2 — East (5, 6) → South (5, −3). Same x, so distance = |6 − (−3)|. How many blocks?

blocks

Q3.3 — Total subway length = segment 1 + segment 2. How many blocks of track in all?

blocks

Level 1 · Support

Same row (same y)? Subtract the x-values and take the absolute value. Same column (same x)? Subtract the y-values and take the absolute value. Subtracting a negative is the same as adding: 5 − (−4) = 5 + 4 = 9.

Español: Misma fila (misma y): resta las x y toma el valor absoluto. Misma columna (misma x): resta las y. Restar un negativo es sumar: 5 − (−4) = 9.
Level 2 · Enrichment

A rider wants to go straight from North (−4, 6) to South (5, −3), but no diagonal track exists. Why must the train ride both segments (9 + 9 = 18 blocks) instead of a shorter diagonal?

Task 4 · Mirror the District Reflections

The Riverside district sits at R = (3, 5). The plan calls for a twin district that is its mirror image. Reflect the point, then check the picture. Pick the axis on the pad, see the reflection update, and answer the coordinate questions.

x y R (3, 5) R′
Riverside & its mirror twin1 square = 1 block

Choose the mirror axis

Original R
(3, 5)
Mirror axis
y-axis
Image R′
(−3, 5)

Q4.1 — Reflect R = (3, 5) across the y-axis. What are the coordinates of R′? (Format: x, y)

( , )

Q4.2 — Now reflect R = (3, 5) across the x-axis instead. What are the coordinates of R′? (Format: x, y)

( , )

Level 1 · Support

A reflection flips a point to the opposite side of the mirror line. Across the y-axis: keep y, change the sign of x. Across the x-axis: keep x, change the sign of y. Only one number changes sign.

Español: Reflejar sobre el eje y: conserva la y, cambia el signo de la x. Sobre el eje x: conserva la x, cambia el signo de la y. Solo un número cambia de signo.
Level 2 · Enrichment

Reflect R across the y-axis, then reflect that image across the x-axis. Where does R end up, and what single move from (3, 5) would get there in one step?

Task 5 · Master Plan Summary Pull it together

Fill in the official summary line so the city council can read your plan at a glance. Use your earlier answers.

Lowest site
Subway track
Mirror twin (y-axis)

Check your work in Tasks 2–4, then press Update summary to fill this board before you submit.

City Engineer's Sign-off

When every plan check is approved, file your master plan with the city. Enter your name in the field below, then press Submit plan & grade to save your score as a PDF or DOC.

Performance Rubric — City Grid Engineer (6.NS.C.5–8)

Level Score Descriptor
4 — Exceeds 10–11 / 11 Names coordinates in all four quadrants, orders signed elevations and applies absolute value correctly, computes same-line distances, and reflects across both axes. Can explain the difference between order and absolute value and generalize the reflection rule.
3 — Meets 8–9 / 11 Correctly handles most plan checks with at most two sign or arithmetic slips. Completes the route and at least one reflection accurately.
2 — Approaching 5–7 / 11 Plots and names simple points but mixes up quadrant signs, or confuses "less than" with absolute value, or changes both signs in a reflection. Partial distance work.
1 — Beginning 0–4 / 11 Few correct coordinates. Misreads signs or the grid. Needs reteaching on plotting, integers, and absolute value.