In doing the unit test, I think I work smart AND hard because I answered the hard questions first, then the easy ones lastly the medium questions but I didn’t finish the test in one class period so it means that I don’t work effectively enough. I also forgot about relatively prime numbers, now I know what it is. In the future I will answer the questions that I’m confident with then I can spent the rest of the time solving the ones I’m not confident. I also will study the vocabulary words more.
In math, our unit question is ‘How do we work smart not hard?’ and we learned ways to work smart not hard. Here are some ways that we learned this unit.
1. Know and use divisibility rules. (open this to see my divisibility rules post).
2. Use models to show your thinking (e.g. ♦♦ + ♦♦ = ♦♦♦♦)
3. Write notes neatly and be organize so you can understand your notes easyly.
4. Use mental math strategies to help you solve math problems.
5. Search information from internet, people’s blog or videos from youtube about strategies in solving math problems.
6. Use ladder method or other method of prime factorization to find the CF, GCF, CM and LCM of numbers.
7. Memorize prime numbers from 1 up to 100.
8. Look for patterns in a problem.
9. Understand mathematical words: prime, composite, odd, even, abundant, perfect, etc.
10. Look for other solved problems that are similar with the problem that you solve.
In math, we learn about divisibility rules, we learn divisibility rules for 0, 1, 2, 3, 4, 5, 6, 9, 10 and 12. Here are the divisibility rules:
DIVISIBILITY RULES
1. All # are divisible by 1. The Identity Property. Ex. 345 ÷ 1 = 345
2. If a # is an even #, then the # is divisible by 2. Ex. 342 ÷ 2 = 171
3. If the sum of a # is divisible by 3, then the # is. Ex. 453 ÷ 3= 151 [(4+5+3) ÷ 3= 4]
4. If the 2 last place value of a # is divisible by 4, then the # is. Ex. 4220 ÷ 4 = 1055
5. If the last place value of a # is 0 or 5, then the # is divisible by 5. Ex. 450 ÷ 5 = 90
6. If a # is divisible by 2 and 3, then the # is divisible by 6. Ex. 426 ÷ 6 = 71 [(426 ÷ 2 = 213), (426 ÷ 3 = 142)]
9. If the sum of a # is divisible by 9, then the # is. Ex. 216 ÷ 9 = 24 [(2+1+6) ÷ 9 = 1]
10. If the last place value of a # is 0, then the # is divisible by 10. Ex. 450 ÷ 10 = 45
12. If a # is divisible by 3 and 4, then the # is divisible by 12. Ex. 22,236 ÷ 12 = 1853
In Math class, we watched a video about Ma and Pa who are not multiplying, add and divide in wrong way so they got the wrong answer. Here are their mistakes:
By Livia
By Livia
By Livia
In math, I learn about scientific notation. In learning scientific notation, I also learning about density, powers, exponents and base.
First do you know what is scientific notation? Scientific notation is when we make very large number into smaller number, e.g. 1,000,000,000 =109. Let’s solve this problem: Our planet mass is 5,973,600,000,000,000,000,000,000 kg and of course it’s too hard to mention this number so we use scientific notation, the way we start from the last digit and hop to the previous digit and we stop right at the number before the coma them change the coma into decimal point after that we count the amount of hops so in this problem we got 24 hops and so the final result is 5.9736 x 109
Lets talk about density. Density tells us when something will float or sink in water. Everything have a density, the density of water is always 1 g/ml. To find a density of an object we need to divided it’s mass with it’s volume then we get the density. We can know the something is floating or not in water only with finding out the density. If something has a density that is less that 1 or lower that the density of water it will definitely float but if something has the density more than 1, it will sink.
And those are the things that I have learn in math about scientific notation
In Math class, we learn about zero place holder. We asked to watch a short video and answer the following questions:
1) Why is zero a hero?
If we run out of digits we can start all over again into a new place value with 0 (123456789 10).
We can count as many as we want with zero even to infinity.
2) What happen if there is no zero?
Without zero, we cannot count or reach big numbers and also without zero we can’t go to bigger place value besides ones.
3) Why is it sometimes called “A Zero Place Holder”?
It is because, the zero will be the ticket to go to the next place value example: 10>100>1000>10000
And that is the information that we got from the video about ‘ZERO’. Hope you realize how important ’0′ is in our number system.
I am going to explain about what I know about multiplication. Multiplication is part of counting in math. the symbol when we multiple something is ‘x’ but not just that bacause if we use exponents (e.g 106), it also can called product of something (e.g what is the product of 2 and 3? ans: 6), or even people use ‘.’ to represent the symbol of multiplication.
Multiplication work like this: We want to know what is the answer of 2 x 8. 2 x 8 = 2 times 8 / there are 2 eights, if we want to use the hard way it goes like this: 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 = 2 x 8 = 16.
I think multiplication is really important to learn because without knowing multiplication, we cannot solve some of our daily life problem that have connection with math, although we can but in the long way like for example: I, my mom, my dad, and my 2 little brothers drink 10 glasses of water everyday. How many glasses of water do they drink in a week altogether? Solution: 5 people, 10 glasses each (each day), 7 days. 10 x 5 = 50, 50 x 7 = 35. They drink 350 glasses of water in a week. Another example of real life problem that use multiplication is: My Aunt have a small shop. She sells cakes. She sells the cake Rp. 50,000 each no matter what size. One day, a customer came an order 5 cakes. She don’t have any calculator. How many should the customer pay? Solution: 50,000 each cake, 5 cakes. 50,000 x 5 = 250,000. The customer must pay Rp. 250,000.
