Lemonade-Ed - Lesson Plan for Measurement, Accuracy & Precision

Lesson Plan: Accurately Using Measuring Equipment

Hei Mahi (Do Now)

Do Now: S1.2 Knowledge Book A pg 8

Mrs. Heald needs to measure her height and the height of the tallest person in the room (record height without units).

Measuring
- - Quantitative measurements involve numbers
  - We need to accurately measure things so that we can compare and make conclusions about our observations.
Units
- - All measurements need units. They give meaning to numbers.
Measuring common quantities
- - pH - measured using pH indicator and a reference chart
  - length and width - measure by choosing the most accurate ruler / measuring tape possible
  - temperature - measured using either a glass thermometer or an infrared thermometer
  - volume - measure by choosing the most accurate instrument (syringe, measuring cylinder)
  - mass - electronic balance
Reading the scale

Mrs. Heald will pass around some measuring cylinders. You will either get a 10 mL one or a 100 mL one.

Which way does the scale read?
What does each division (line) on the scale stand for?
- - What are the units?
  - How do you know?
Use a whiteboard marker to draw on:
- - 10 mL cylinder: 2.0 mL, 5.6 mL, 8.1 mL
  - 100 mL cylinder: 20 mL, 56 mL, 81 mL

Accuracy = taking measurements that are as close as possible to the "real value"
Precision = taking measurements that are consistent with each other.
- - The measuring instrument that gives you a measurement with more decimal places is more accurate than an instrument that gives you a measurement with less decimal places.
  - Accurately measure quantities by starting all your measurements from zero.
Errors in measurement affect accuracy and precision