## Algebra in Math Class (R5)

Algebra is the way in which the letters or even other general symbols are used to represent numbers and quantities. It quite benefits to human daily life because it could play a role of representing other quantities that people are not sure about. First time, It might seem to be complicated for some students as the way it looks, including me. But as you explore future more, you could easily discovers the way to express those problems. In the algebra expression, there are relationship between positive and negative, too. As part of humanity, we usually don’t know the exact quantities of the things. However, as in mathematics, you can replace a letter to represent the the quantity you want to figure it out.

Find the value of y when x=10

y = 9x/5

y = 90/5

y = 8

## What is Percentage?

Percentage was a main topic that we focus on in my class this round. In my opinion, percent is an important part of our every life. It relates to the discount in a shop, the charge or interest in the banks, increase in value, commission, etc. For example, after I’ve learned how to calculate percentage, whenever I go to different shops with discount, I know really clearly of how to calculate which of how much the shop has discounted.

Below are some examples of percentage, Please take a guest of the right answers

• What is 40% of 300?
• 110
• 115
• 120
• 130

• Votey earns \$800 a month. She gives 20% of the money to charity. How much money does Votey give to the charity?
• 200
• 160
• 300
• 320

## Math, Round 3

Basically, this is our third round of the year. In Math class, we’ve started our Primary Mathematics 5B  both in Textbook and Workbook. In addition, this round we were mainly focusing on decimal. We’ve also learned different courses such as add, subtract, multiply and divide decimals. On the other hand, we discovered multiple shortcut ways and rules to solve our problems easily. Small activities, teamwork, discussions have been introduced to us during learning decimal.

Examples 1: Multiple and divide by 10, 100, 1000

0.5  x  10 = 5

0.05  x  10 = 0.5

0.005  x   10 = 0.05

x  10 moves the decimal 1 place to the right

x  100 moves the decimal 2 places to the right

x  1000 moves the decimal 3 places to the right

Example 2: Multiple by  0.1         0.01          0.001

40  x  0.1 = 4

40  x  0.01 = 0.4

40  x  0.001 = 0.04

x  0.1 moves 1 place to left

x  0.01 moves 2 places to left

x  0.001 moves 3 places to left

## Math, Round 2

In the second round of the year, we finished our 5 A textbook and workbook. One of the lesson in math class is about geometry which mainly talking about perimeter, Area and surface area. Along this lesson, we did activities such cutting out paper into shapes and exercise in the textbook and workbook. In the geometry lesson, we focused on some shapes such as square, rectangle, triangle and parallelogram. I think find perimeter or area of the shapes is not really difficult, unless you know the rule of solving the problems of each shape. One of the interesting lessons is surface area. There are several shapes such as rectangular prism, triangular prism, rectangular pyramid and triangular pyramid. By knowing the area of each face, we can know the the surface area of the shapes.

For example: A cube with the length of 5.

Surface area: 6 x (5 x 5) = 150

In addition, in math class we learned algebra course through computer science which in a website called code.org. In the course, there are fun activities and problems that we can do. I am enjoying using this website to learn algebra through computer science.

## Math

As the first term of the year, in the first week our teacher told us to create a poster about encouragement words to hang in the classroom. The statement was about “Make the most of your learning”. It was a really great statement in my opinion. Whenever I looked at the wall and see that poster, it is always motivate and inspire me to work hard, listen to my teacher and make the most of all of my learning and do my best with my learning.

This term in math class, we’ve finished half the workbook already. I’ve learned about more calculations with whole numbers, fractions including addition, subtraction, multiply and division. Throughout these lessons, we did many many activities, also the exercise including word problems in the textbook and workbook. On of my favorite unit was about more calculation with whole numbers because in order to calculate the expression with different operation signs, we need to do it by rules which means not to plus, time,subtract, or divide one by one from the left. The rules says that do the multiplication or division from left to right, then addition or subtraction from left to right. You can see one of an example here!!

88 – 8 × 6 ÷ 3 – 80 ÷ 8 × 7

88 – 48 ÷ 3 – 10 × 7

88 – 16 -70

2 One of a website that we use during our class is Khan Academy. I think it is very useful and convenient to use of our learning. Our teacher often add assignments to us in Khan. In my free time, I often do the exercise and assignments on Khan because if we don’t know of the answer, there are videos for us to watch.