Posted by David Wetzel
Cola or Water?
One way to peak the interest of your students is to conduct an experiment using objects of things that they encounter often or even on a daily basis.
This investigation is designed to determine if plants prefer cola or water to grow.
An Inquiry Investigation
Materials
- 2 small plant pots with saucers
- paper for data collection
Procedures
- Place each plant in a small plant pot
- Label one pot - water
- label the other pot - cola
- Add water to the pot labeled water until the soil is moist
- Add cola to the pot labeled cola until the soil is most
- Take pictures of both pots
- Measure and record the height of the both plants, along with any other observations made of the two plants
- Make daily observations of the plants for 5 days, record observations and take pictures
- Ensure the soil in both plants remains slight moist throughout the investigation
Findings
Answer the following questions:
- Write a short story describing all observations and what happened to both plants.
- Which plant was surviving after 5 days?
- Why was the plant that was not surviving, dying?
- What would happen if diet cola was used instead of cola?
- What would happen if another type of carbonated drink were used instead of cola?
- How could the investigation be redesigned to test if plants like cola or water? (hydroponics is one alternative)
Typical Results
Students will find that acidic level of cola, along with the other ingredients in cola, will kill the plant only given cola.
Resources
20 Questions to Ask Students in Science
Problem Solving and Science Process Skills
Effects of Acid Rain on Plants
Posted by David Wetzel
Number Classifications
We use numbers everyday of our lifes. Based on their characteristics, they are classified in groups.
Real Numbers – All kinds of numbers that you usually think of – from bus route numbers, to your weight, to pi and even the square root of pi! In short almost everything!!
Imaginary Numbers – Have you ever tried finding the square root of -1? If you haven’t, try it on your calculator. It might show an error (if it is a dumb calc) or it might show an ‘i’. That little ‘i’ is called an imaginary number. In short square roots of negative numbers make imaginary numbers.
Complex Numbers – It’s rather simple! Make a combination of Real and Imaginary numbers and voila! You get a Complex number. Stuff like 3+2i or 3/4i make up complex
numbers. Just think of it when you mix a real number with an imaginary one, things do get a bit complex!
Rational Numbers – Any number that can be written as a fraction is a rational number. So numbers like ½, ¾, even 22/7 and all integers are also rational numbers.
Irrational Numbers – Simply the opposite of rational numbers i.e. numbers that cannot be written as fraction, like square roots of prime numbers, the golden ratio, the real value
of pi (22/7 is a mere approximation not the real value of pi) are irrational numbers Integers – Any number that is not a fraction and does not have a tail after the decimal point is an integer. This includes both negative as well as positive numbers as well as zero.
Fractions – Numbers that are expressed in a ratio are called fractions. This classification is based on the number arrangement and not the number value. Remember that even
integers can be expressed as fractions – 3 = 6/2 so 6/2 is a fraction but 3 is not.
Proper Fractions – Whenever the value of the numerator in a fraction is less than the value of the denominator, it is called a proper fraction. i.e. it’s bottom heavy.
Improper Fractions - Whenever the value of the denominator in a fraction is less than the value of the numerator, it is called a proper fraction. i.e. it’s top heavy.
Mixed Fractions – All improper fractions can be converted into an integer with a proper fraction. This combination of an integer with a proper fraction is called a mixed fraction.
Natural Numbers – All positive integers (not including the zero) are Natural numbers. Simply put, whatever you can count in Nature uses a natural number.
Whole Numbers – All positive integers inclusive of the zero are Whole numbers. Not a big deal different from Natural numbers.
Even Numbers – All integers that end with a 0, 2, 4, 6, or 8 (including the numbers 0, 2, 4, 6 & 8 themselves) are even numbers. Note that ‘0’ itself is an even number. Also note
that negative numbers can also be even so long as they can be integrally divided by 2.
Odd Numbers – All integers that are not even numbers are odd number.
Prime Numbers - A natural number, more than one, which has exactly two distinct natural number divisors: 1 and itself - is called a Prime number. There can be infinite
prime numbers.
Composite Numbers – A positive integer which has a positive divisor other than one or itself is a composite number. In other words, all numbers that are not prime are
composite.
Source
Adapted from LazyMaths
Comments:
Filed Under: Math
Posted by David Wetzel
Rock Erosion by Plants
Erosion is the wearing away of soil and rock, and the down-slope movement of soil and rock. Some factors that influence erosion include gravity, glaciers, water, wind, ice, and waves.
In this investigation, your students will determine if rocks are eroded by plants.
Rock Erosion and Plants
When plants grow in soil-filled cracks of rocks, their roots may push on the sides of the crack, widening it and eventually breaking the rock apart.
Materials:
- milk carton or similar disposable container
Procedure:
- Cut the top off of a milk carton to form a container about 2½ inches high.
- Prepare plaster of paris according to directions and fill the container.
- Push a bean seed that has been soaked in water just under the surface of the plaster and observe for several days.
- Students describe what they observe.
Questions For Students:
- What would happen if the beans were in the crack of a rock?
- What if they were the seeds of a tree, rather than a bean plant?
- Can plants break apart rocks?
- What type of erosion was caused by the beans?
Science Behind this Investigation
When plants grow in cracks in rocks, their growing roots may produce enough force to break the rock.
