(EF06MA13) Solve and elaborate problems involving percentages, based on the idea of proportionality, without making use of the “rule of three”, using personal strategies, mental calculation and calculator, in contexts of financial education, among others.
Contextualization and polling
Bring to the room through a real case a situation involving percentage. If you prefer, the teacher can use storytelling as a resource. After initial motivation, ask students if they have seen or been through a similar situation.
At this point, the teacher raises the students' previous knowledge about the topic.
Expository class
The concept of centesimal fraction must be resumed, relating percentage to the idea of fraction with denominator 100. The % mathematical symbol must be entered, as well as the decimal form.
The teacher initiates strategies for solving problems that involve the idea of x % of a quantity. Preferably use situations involving monetary values.
Presentation of the strategies for multiplying the quantity by the centesimal fraction and decimal number.
If you have a textbook or other support material with exercises, ask students to solve and use the strategies that are favorable to each problem situation.
If possible, when preparing the lesson, ask students to bring calculators. Introduce percentage functions in these devices and modes to calculate percentage with the aid of electronic calculators.
Display the video in the room, if a projector is available. Optionally, you can send the link through and ask students to watch as homework.
Search
Students should bring clippings from newspapers, magazines or price catalogs with situations involving percentage, such as discounts, for example.
These clippings will be pasted on sheets and, below the collages, the student will perform and present the calculation, handwritten, using the strategy that is most convenient for him.
Time to complete the survey: at least one week.
Introduction
Presentation of the equality symbol, its concept and properties.
Use numerical examples to demonstrate the properties of equality.
It is possible to use blackboard or slides for exposition.
Equality Battle game
Number of players: 2
Mode: Double
Material: letters with the digits from 0 to 9. At least three letters are suggested for each digit.
Player A will manipulate the first member of equality while player B will manipulate the second.
rules and procedure
Step 1
The player who starts takes a card.
Example: 8
step 2
Player B draws two cards that, when added or subtracted, result in the value of the card drawn by player A.
Examples:
4 + 4 = 8
8 + 0 = 8
9 - 1 = 8
7 + 2 = 8
Thus, it is up to player B: to remove the cards, decide which operation to use and perform the calculations.
If he does not have cards that satisfy the equality, player B must continue drawing cards from the block.
Once equality is satisfied, player B uses one of his cards or, if he has none, removes one from the block of cards and presents it to player A.
step 3
This time it's up to player A to remove the cards from the block or use his own, until he manages to satisfy the equality, adding or subtracting.
The game ends when there are no more cards left and whoever has the fewest cards in his hand wins the game.
Container in the form of a quadrangular prism with a capacity of 1 liter (suggestion: milk carton), important to come home clean;
Capacity meter with a minimum of 1 liter (suggestion: blender cup).
Pencil, notebook or sheets for note-taking and sketching.
School rule.
Funnel
Expository theoretical class
The teacher should start studying linear length, area and volume measurements. The capacity quantity must also be previously worked out.
Present on the board or projection the mathematical model for calculating the volume of the parallelepiped.
Interestingly, length and capacity units have already been addressed, as well as unit transformation.
Experiment
Using the ruler, students should measure the dimensions: length, width and height of the container. These measurements must be written down in a notebook or sheet using the centimeter as the unit of measurement and one decimal place of precision.
Calculate the volume of the container using the mathematical model for calculating the volume of quadrangular prisms.
The volume must be expressed in cubic centimeter units.
Students must fill the meter with 1 liter of water and then pour it into the container.
Conclusion
The teacher should conduct the findings, encouraging students to develop a relationship between measures of volume and capacity.
To close, the teacher should write it down on the board and ask the students to record it in their notebooks.
1000 cm³ = 1000 ml considering water as a fluid.
continuity suggestions
From this activity, explore other relationships such as cubic meter x capacity, and other pairs of units.
The concept of density can be worked on when raising questions about the validity of these relationships for other fluids and materials.
Methodology
Expository and theoretical class on potentiation and its properties.
The teacher uses the board to describe transformations and potentiation properties. Next, the approximation of numbers to the power of 10 is discussed.
If necessary, the teacher can use available resources such as books and handouts.
The PDF with the activities can be used as a homework assignment, class assignment or even as an assessment tool.
Blackboard
painting brush
projector (optional)
Support material such as book and handout (optional).
Notebook or sheet for registration.
Pencil, pen and eraser.
Sheet for table production.
Sheet or computer for graphic production.
Scale.
Colored pencils.
Open space such as a court or patio, if possible.
Material for scratching the floor, such as chalk.
Video
Expository class
The teacher should discuss the topics of probability such as:
Probability concept;
Random experiment;
Sample space;
Event.
The video as an initial motivator, can be displayed in the living room, if you have a projector available, or to watch at home.
Experiment
data production
In a space such as a patio, hallway or the back of the room itself, the teacher will supervise the students in the production of the field of activity. Using chalk or material to scratch the floor, students will draw parallel lines to the bottom of the space used, delimiting five strips of the same width.
The strips must be named A, B, C, D, E and have the same width. We suggest a minimum of 25cm for each.
Taking a certain distance, students will throw the covers towards the tracks. The amount of caps that each student can launch is up to the teacher, we suggest that a total of 100 caps are launched.
Data collection and recording
Afterwards, students must collect, count and record the number of caps that stopped in each lane.
The record must be performed in a table, made by the students themselves, as in this example:
| RANGE | THE | B | Ç | D |
|---|---|---|---|---|
| THE AMOUNT |
Calculation of probability through frequency
Students should calculate the probability as the ratio of the total caps to the amount recorded for each band.
graphic production
Students must present a bar graph where each column represents the amount of caps recorded for each band.
It is important that the teacher supervises this step in which, according to the available resources, the task can be performed with the help of a sheet and ruler, or in electronic spreadsheets.
