Worked example · Science and Technology · Year 3
DCF: Data and computational thinking → Problem-solving and modelling
Also assessed, LNF: Numeracy → Learning about geometry helps us understand shape, space and position, and learning about measurement helps us quantify in the real world → Angle
A secure Year 3 response, annotated so you can see which success criterion each part meets. It is also the answer key. Program A ends at the layered rock; Program B ends at the speckled rock; Cai’s bug is card 7; Megan is missing one F; the fixed program is R F F F F F L F. Any Step 4 route that avoids the soft sand and the crater is correct.
F F F moves the rover up 3 squares. It reaches the layered rock.
Each card followed in order. Evidences criterion 1.
(a) After R the rover faces right. It has made a quarter turn clockwise.
(b) It moves 3 squares right and reaches the speckled rock.
The pupil knows a turn does not move the rover to a new square. Evidences criterion 1.
(a) Cai’s rover gets to the bottom right corner, then card 7 (R) turns it to face down. Card 8 tries to drive it over the cliff. Card 7 should be L.
(b) Megan’s rover only goes 4 squares right, so when it turns and goes up it drives into the soft sand. She needs one more F before the L.
(c) R F F F F F L F
Each bug found by following the program until it goes wrong, then fixed. Evidences criterion 2.
| Card | Letter | Turn |
|---|---|---|
| 1 | F | |
| 2 | F | |
| 3 | L | quarter turn anticlockwise |
| 4 | F | |
| 5 | F |
Tested: Yes, the rover reached the speckled rock.
Another correct route is F L F F R F (up 1, left 2, then a quarter turn clockwise and up 1). Wrong: L F F R F F, because the first F drives into the soft sand. Evidences criteria 3 and 4.
| Starts facing | Cards | Ends facing | Name the turn |
|---|---|---|---|
| up | R | right | quarter turn clockwise |
| up | L | left | quarter turn anticlockwise |
| up | R R | down | half turn clockwise |
| right | L L | left | half turn anticlockwise |
| left | R | up | quarter turn clockwise |
(a) 1 quarter turn clockwise (R) and 1 quarter turn anticlockwise (L).
(b) Both face left. Three quarter turns clockwise end in the same place as one quarter turn anticlockwise. Ffion’s program is shorter.
Turns counted and named with the right words. This is the numeracy (angle) evidence. Evidences criterion 4.
R, Repeat 5 times: F, L, F
That is 4 instructions instead of 8, so I saved 4.
The repeated card is spotted and replaced with a loop. Evidences criterion 5.
Base to layered rock to speckled rock to red rock, one correct program: F F F (layered rock), R F F F (speckled rock, facing right), F F R F F (along the top to the right edge, a quarter turn clockwise to face down, then down 2 squares to the red rock). Going down from the speckled rock and then right does not work: it drives into the soft sand. Any route that never touches the crater or the soft sand is correct.