Convert before you compare
A label uses metric units. Put each value in the requested unit.
250 cm of table length → ___ m
0.75 L of water → ___ mL
1,500 mg of material → ___ g
A 2.4 m safety boundary → ___ cm
Response-time board
Four students timed how long it took to stop, step back, and raise a hand after a teacher’s signal. Lower time is not automatically “better”: the response must also be calm and correct.
| Student | Trial 1 | Trial 2 | Trial 3 | Mean |
|---|---|---|---|---|
| Amber | 4.2 | 4.0 | 4.4 | |
| Iris | 3.1 | 7.9 | 3.3 | |
| Sage | 4.8 | 4.7 | 4.9 |
Find each mean to the nearest tenth.
Which student has an outlier? What should a scientist do with that trial?
Why is “fastest” not enough evidence to decide who responded best?
Read the safety-check graph
A class recorded how many students could name the next safe move after four short scenarios.
| Scenario | Students correct | Students asked |
|---|---|---|
| Spill | 18 | 24 |
| Broken glass | 22 | 24 |
| Heat/electricity | 15 | 24 |
| Unsure | 24 | 24 |
Which scenario needs the most review? Use one number as evidence.
What percentage of the class answered the “heat/electricity” scenario correctly? Show your setup.
Write one sentence that distinguishes evidence from an opinion.
Safety math is decision math
A classmate says, “Only 2 out of 24 missed it, so we can skip the review.” Use the table to disagree or agree with evidence.
Finish the sentence: “When I do not know the next step, the safest calculation is…”
Answer key — teachers
Part A
- 2.5 m
- 750 mL
- 1.5 g
- 240 cm
Part B
Amber = 4.2 s; Iris = 4.8 s; Sage = 4.8 s. Iris has a 7.9 s outlier; flag it, investigate what happened, and do not silently delete it. A safe response is correct, calm, and repeatable — not merely fast.
Part C
Heat/electricity needs the most review: 15 of 24 correct. 15 ÷ 24 × 100 = 62.5%. Evidence names a measured count; opinion adds a judgment without showing its basis.
Part D
Two missed answers still matter because the class needs a reliable response, not a vibe. The sentence should point to pausing and asking the teacher before acting.