Here are our classroom rules.
Remember that F.A.I.L means First Attempt In Learning.
From last time we know:
- What a cuboid is compared to, for instance, a cube.
- How to calculate the volume of a cuboid (and a cube).
- Know how to round off to a given number of decimal places.
Can I calculate a volume of a two-dimensional shape, like for example a rectangle?
Is it enough information if I know the length of one side in a cube to calculate the volume?
The general rounding rules are:
- If a digit after the one being rounded off is less than 5, we round down.
- If a digit after the one being rounded off is 5 or more, we round up.
- Round 254 to the nearest 10th.
Since the 5 is the 10th, we look at the number after which is a 4. Since it is a 4 we round the number down, i.e 254 to the nearest 10th is 250.
2. Round 7.2614 to 1 decimal place.
Since one decimal place is where we have a 2, we look at the number after the 2 which is a 6. Since it is a 6 we round the number up, i.e 7.2614 rounded to 1 decimal place is 7.3.
- Know how to round off to a certain number of significant figures.
- Understand the difference between the concepts decimal places and significant figures.
- Know that you always should round to three significant figures if nothing else is stated (in the IB).
Guess the height of the person sitting next to you.
Give your answer correct to 3 significant figures in centimeter.
Give your answer correct to 4 significant figures in centimeter.
Which measurement ”tries” to be more exact than the other one?
Convert the height into decimeters, meters and kilometers. Has the values accuracy changed?
If you want to be prepared, watch the video from Khan academy about significant figures.
Back to the examination question.
Work in book, p. 48
2E.1, 1-2 every other