Solving Problems that Involve Subtraction

Hi, kids. This e-tivity is about understanding what mathematical operation is needed to get the answer of a word problem. It's the second from a series of e-tivities about problem solving. By the end

• you will be able to identify what words indicate subtraction,
• you will learn how to subtract fractions.

Average online time: 25 min

Average offline time time: 10 min

1) What words do you think indicate subtraction in a word problem?
Share with your classmates your ideas, write down your message and the click the shout button

2) Consolidating our thinking

Let's watch the following video, please turn on your speakers



Create your own video slideshow at animoto.com.


3) Solving a word problem

Remember that there are at least three questions you need to ask yourself in order to solve a word problem:

1) What numbers are needed to answer the question?

2) What mathematical operation(s) is/are needed?

3) Does my answer make sense?

María is placing some wood fence along a path that is  10   1/3 feet long.  After finishing her daily work, she has already completed  5   2/3  feet. How many feet are there left for completing the fence?

a) What numbers do I need to answer the question? 10  1/3 and 5  2/3

b) What mathematical operation is needed? subtraction because of the words how many....are left

c) Subtracting 10  1/3  &  5  2/3

d) Answering the question.  There are left 4  2/3 feet.

5) Your Task

You need to invent a word problem that requires subtraction to be solved (hint: use one of the key words here explained). Once you have invented your problem, you need to solve it by following these four steps:

a) Understanding: What numbers do I need to answer the question?

b) Planning: What mathematical operation is needed?

c) Solving the problem

d) Answering the question

Do not forget to post your comment including your word problem and the steps a), b), c), and d) you used to solve it.

See you around!

Solving Problems that Involve Addition

Hi, kids. This e-tivity is about understanding what mathematical operation is needed to get the answer of a word problem. It's the first from a series of e-tivities about problem solving. By the end

• you will be able to identify what words indicate addition,
• you will learn how to add fractions and mixed numbers.

Average online time: 25 min

Average offline time time: 10 min

1) How do you solve a word problem?

Share with your classmates the strategies you use to solve a word problem, write down your message and the click the shout button

2) How do "experts" solve a word problem?
Let's watch the following video, please turn on your speakers

There are at least three questions you need to ask yourself in order to solve a word problem:
1) What numbers are needed to answer the question?
2) What mathematical operation(s) is/are needed?
3) Does my answer make sense?

3) Choosing the mathematical operation to be done
In other words, we need to decide if we have to add, subtract, multiply or divide.
Let's play the following fun game to find our what words indicate addition. Once you are sure about the word, click the check  button to continue with the next word


As you see the following words indicate that addition is required: sum, plus, in all, altogether, additional, extra, increase, combined, add.


4) Solving a word problem
Carlos and María will prepare a delicious milkshake. Carlos has 4  3/5  cups of vanilla ice-cream and María has 8  4/5 cups of chocolate ice-cream. Altogether, how many cups of ice-cream do they have?


a) What numbers do I need to answer the question? 4  3/5 and 8  4/5


b) What mathematical operation is needed? addition because of the word altogether


c) Adding 4  3/5  &  8  4/5




d) Answering the question. Altogether Carlos & María have 13  2/5 cups of ice-cream


5) Your Task
You need to invent a word problem that requires addition to be solved (hint: use one of the key words here explained). Once you have invented your problem, you need to solve it by following these four steps:


a) Understanding: What numbers do I need to answer the question?
b) Planning: What mathematical operation is needed?
c) Solving the problem
d) Answering the question


Do not forget to post your comment.


See you around!

Finding the 2/3 of a right angle

Hi, kids. This e-tivity is about angles. By the end

• you will be able to find an angle using as benchmarks the right and straight angles,
• you will learn how to multiply fractions by whole numbers.

Average online time: 15 min

Average offline time time: 10 min

1) DEFINING ANGLES

An angle is the figure formed by two line segments or rays which intersect at a point called vertex. We use degrees (º) to measure the size of an angle.

2) DEFINING OUR BENCHMARKS

For this e-tivity we will use as benchmarks the right angle and the obtuse angle. A right angle has a measure of 90º and a straight angle has a measure of 180º.

3) FINDING THE 2/3 OF A RIGHT ANGLE

METHOD 1

You need to multiply the fraction given by the measure of a right angle.

METHOD 2

2/3 means that I divide the given angle into three parts, and then I take two of them.

ANSWER

The 2/3 of a right angle correspond to 60º.

YOUR TASK

1) Select the angle you will use as benchmark

2) Choose a method

3) Pose a question similar to the one here on this blog entry (you are not allowed to use 1/2)

4) Solve it :)

Post your comment including answers to numerals 1, 2, 3 & 4.

See you around!

Magic Squares

Hi, kids. I have had so much fun creating this e-tivity. I'm sure you'll find it enjoyable as well. This e-tivity is about magic squares, by the end you will be able to

• analyze a situation that involves number sense,
• devise a strategy to fill in a magic square
• explain your strategy to your peers
• recognize that different cultures have brought  ideas, inventions, games to the math field

Average online time: 25 min
Average offline time: 20 min


1- Getting Started
Have you heard about the term brain teaser?
Let's watch this video together. Please, turn on your speakers.

2- Discovering Magic Squares

Analyze carefully the following square.

Do you see any special pattern? (if you need a hint, click here)

Do you have an answer? Compare it with this one.

As you noticed above, a magic square is a rectangular array of numbers so that each column, row and both diagonals have the same sum. In addition, each number appears just one time.

3 - After the origins of Magic Squares

After the origins of Magic Squares on Prezi

Now, it's time for you to seach another game, idea, invention that a culture different from ours had brought to the Math field. Be ready to discuss it in class.

 

4- Let's try one out!

Are you ready for the challenge?

Choose the Magic Square you feel more comfortable with. They have been selected according to the difficulty level they entail.

Easy

Medium

Hard

5- Reporting your findings

• a) Print the puzzle you chose or copy it on your notebook, and bring it next class. Be ready to explain your teacher the strategy you chose to fill in the Magic Square.

See you around!

Doing operations with fractions

Hi, kids. This e-tivity is about adding, multiplying, subtracting and diving fractions.

By the end, you'll be able to

• explain how to add/subtract/multiply/divide fractions.
• use examples to show your understanding of math concepts.

Average online time: 15 min
Average offline time time: 20 min

Create your own video slideshow at animoto.com.


TASK

1) Select one mathematical operation: +, -, x, or /

2) Explain how you will perform that operation using fractions

3) Write down an example to support your explanation

Post your comment including answers to all the above numerals

See you around!

Useful links:

http://www.mathsisfun.com/fractions_addition.html

http://math.com/school/subject1/lessons/S1U4L4GL.html

http://math.com/school/subject1/lessons/S1U4L3GL.html

http://www.mathsisfun.com/fractions_division.html

Visual Thinking

Hi, kids. This e-tivity is about developing your visual thinking. By the end

• you will be able to strengthen your visual intelligence

Average online time: 15 min

VISUAL THINKING

"Thinking is taking in information from the outside world and from within ourselves and processing it with our brain. There are three main ways of thinking that correspond to the senses:

• Hearing – auditory thinking
• Seeing – visual thinking
• Feeling – kinaesthetic thinking.

Visual thinkers think most efficiently, when material is presented to them using diagrams, flowcharts, time lines, films, and demonstrations.

Visual thinkers tend to be spatial and have an eye for size, space and relationships.

To retain information they often draw it as a diagram." (Sword, 2005)

Learners should develop all three types of thinking in order to enhance their learning process.

BIBLIOGRAPHY

Sword, Lesley (2005). The Power of Visual Thinking. Retrieved on February 6, 2010 from http://giftedservices.com.au/visualthinking.html

TASK

1) Choose two out of the three shapes shown below.

2) Count the number of cubes in each shape.

Post your comment answering numerals 1 & 2. See you around!

Solving word problems involving fractions

Hi, kids. By the end of this task, you'll be able to:

1. apply the concept of part-to-whole relationships to solve daily life problems, &
2. identify how other classmates solve this type of problems.

Average online time: 15 min
Average offline time: 15 min

Below you will find three problems involving fractions. Choose one of them and answer it. Do not forget to explain how you got the answer.
See you around!

PROBLEM 1: There are 24 hours in a day and scientists tell us that we should sleep for 3/8 of the day. How much time should we spend sleeping?

PROBLEM 2: The National History Museum has collected 125 dinosaurs. George has collected 3/5 of this amount. How many dinosaurs has George collected?

PROBLEM 3: Luis collected 256 transformers mini-toys but lost ¾ of them on his way to school. When he arrived at school, how many mini-toys did Luis have left?

The Relationship among fractions, decimals, and percents

Hi, kids.  By the end of this activity:

• you will be able to move among fractions, decimals and percents.
• you will understand the relationship among these types of numbers.

Average online time: 20 min
Average offline time: 10 min

1. TOPIC EXPLANATION

Let's remember some basic concepts.

■ A fraction represents how many parts (numerator) we take from the whole (denominator).

■ A decimal is a number that uses place value and a decimal point to show tenths, hundredths, thousandths and so on.

■ A percent means how many parts we take from a hundred.

2. How do we change fractions into decimals?
Let's change 3/4 into a decimal. Divide the numerator (3) into the denominator (4). 

Answer: 3/4 = 0.75

3. How do we change decimals into fractions?

Multiply the decimal by 100, which means moving the decimal point two times to the right
0.75 x 100 = 75%

4. YOUR TASK

Please choose any fraction and then change it first to a decimal number and then to a percent. The only fraction you cannot choose is one whose percent equals 50%.
See you around!

Additional information about the topic available at:

■ http://www.mccc.edu/~kelld/CompFDP.htm

■http://www.bbc.co.uk/skillswise/numbers/fractiondecimalpercentage/comparing/decimalspercentages/

Multiplying Mixed Numbers

Hi, kids. Welcome to the second e-tivity of this academic year. I am sure you will have a great time. This e-tivity is about multiplying mixed numbers, by the end you will be able to

• understand what multiplication is &
• explain to your classmates what procedures to follow when multiplying mixed numbers.

Average online time: 20 min

Average offline time: 10 min

1- Getting Started

Write down in the following shoutbox what you know about fractions. After writing your message, click the send button

2- Understanding what Multiplication Entails
Keep in mind the following facts:

1) Multiplying can be seen as taken a number "x" times, so for instance 3 x 4 means that you take the number "3" four times. In other words, you add 3 + 3 + 3 + 3

2) The result of a multiplication is called the product and the numbers being multiplied are called factors. For instance, in the mathematical sentence 3 x 4 = 12, 
3 and 4 are the factors & 12 is the product

3) When two numbers are multiplied together, the product is the same regardless of the order of the factors.
7/3 x 4/5 = 4/5 x 7/3

4) The product of any number and 1 is that number.
1/3 x 1 = 1/3 

3- Multiplying Mixed Numbers
Method 1
As you watch the following video, write down the steps the teacher uses to multiply two mixed numbers


Method 2
As you watch the following video keep in mind that a mixed number can be written as a whole number plus a fraction. For instance 

In addition,  when you multiply mixed numbers you can use what is called the distributive property.
  

Ready to watch the second video?

4- Checking Understanding

What would be the answer of the following multiplication.

Click here to check your answer.


5- Assessing Understanding: 

Select any two mixed numbers and following whether method 1 or method 2 multiply them.

Write down your answer and explain how you got it. 

Mixed Numbers

Hi, kids. Welcome to the first e-tivity of this academic year. I am sure you will have a great time. This e-tivity is about converting improper fractions to mixed numbers and the other way around, by the end you will be able to

• explain what a mixed number is,
• convert an improper fraction to a mixed number
• convert a mixed number to an improper fraction 

Average online time: 20 min

Average offline time: 10 min

1- Getting Started

Let's complete a crossword to get familiar with the vocabulary of this lesson.
Click here

2- How do we convert an improper fraction to a mixed number?
The following video has audio, please use your headphones or turn on the volume of your loudspeakers


Retrieved from http://www.youtube.com/watch?v=HPetBqWKvZM

3- How do we convert a mixed number to an improper fraction ?

The following video has audio, please use your headphones or turn on the volume of your loudspeakers

Retrieved from http://www.youtube.com/watch?v=IByEp5brtw4

4- Checking Understanding
Choose two out of these three websites and make the activities there proposed. By doing this, you'll become an expert on converting mixed numbers to improper fractions.

4- Assessing Understanding

Now, it's time for you to show what you have understood about this topic. Post a comment taking into consideration the following:

Choose any mixed number and then convert it to an improper fraction. Provide a short explanation about how you did it.


Choose any improper fraction and then convert it to a mixed number. Provide a short explanation about how you did it.

See you around!