1. Measurement

2. 3 Parts to Measurement: 1. a numeric value 2. a unit 3. an estimation of the amount of error

3. How to Measure Correctly… Look at the measurement tool you are using and figure out how many lines it has. Each of the lines is a segment of measurement For example, if you count the number of lines from 0 to 1 on the ruler below you count 10 lines. That means that the smallest unit of measurement is.1 (1/10 lines)=.1 per line

4. How to Measure Correctly… cont’d Once you know what each segment is worth you must make your estimation. For example: Below you can see a thick black line. That black line is between the.2 line and the.3 line. You know this for sure. Next you make your estimation of how far you think it is between the two lines. Below I think that the line is at about.29 cm. I

5. Estimation Rules 1. If the scale increases by a power of 10 (…100, 10, 1, 0.1, 0.01) estimate one digit beyond the scale. Ex: If the scale goes by 10s, estimate to the 1s place. 2. If the scale increases by any other amount (150, 75, 30, 5, 0.2, 0.005, etc) estimate your answer to the last digit represented by the scale. Ex: If the scale goes by 15s, estimate to the 10s place which is the next smallest Power of 10 number.

6. Rule #1 Power of Ten Scale Smallest increment is 10ml. This is a power of 10 Estimate in the ones place Answer is 57ml,58ml or 59ml

7. Rule #2 Not a Power of 10 Scale Smallest increment is 50 ml. This is NOT a power of ten. Estimate in the tens place. Answer is 330ml or 340ml

8. This may be a problem! The smallest increment of the scale is 25ml. This is NOT a power of 10. Where should I stop? Estimate in the tens place because there is not a line for each increment of ten. (Note there is no 60ml or 80ml) Answer is 80 ml

9. English vs. Metric System English System Examples: 1 foot = 12 inches 1 yard = 36 inches or 3 feet One rod = 198 inches or 161/2 feet or 51/2 yards One mile = 63,360 inches = 5,280 feet. Metric based on Powers of 10 10mm=1cm; 100cm=1m; 1000m=1km 1000mL=1L 1000g=1kg People realized the English system was difficult to use. So…. we use the METRIC SYSTEM ONLY!!!