Q&A - P3 Math

[Just4Good]

ChiefKiasu:

From Ai Tong Pri 3 SA1 Maths:


A teacher gave her students some balloons. If she gave 6 balloons to each student, she will have 2 balloons left. If she gave 8 balloons to each student, she will be short of 2 balloons. What is the smallest possible number of students she has?

Try to do this without using ALGEBRA!

Algebra? :? :? :?

What's that? Look's hard. Rather :stupid: than answer the question. (Just Kidding)

[Just4Good]

ChiefKiasu:

From Ai Tong Pri 3 SA1 Maths:


A teacher gave her students some balloons. If she gave 6 balloons to each student, she will have 2 balloons left. If she gave 8 balloons to each student, she will be short of 2 balloons. What is the smallest possible number of students she has?

Try to do this without using ALGEBRA!

Still thinking what is Algebra..... :?

[Just4Good]

ChiefKiasu:

From Ai Tong Pri 3 SA1 Maths:


A teacher gave her students some balloons. If she gave 6 balloons to each student, she will have 2 balloons left. If she gave 8 balloons to each student, she will be short of 2 balloons. What is the smallest possible number of students she has?

Try to do this without using ALGEBRA!

Oh! I got it !




Algebra is a branch of mathematics that uses mathematical statements to describe relationships between things that vary over time. These variables include things like the relationship between supply of an object and its price. When we use a mathematical statement to describe a relationship, we often use letters to represent the quantity that varies, since it is not a fixed amount. These letters and symbols are referred to as variables. (See the Appendix One for a brief review of constants and variables.)

The mathematical statements that describe relationships are expressed using algebraic terms, expressions, or equations (mathematical statements containing letters or symbols to represent numbers). Before we use algebra to find information about these kinds of relationships, it is important to first cover some basic terminology. In this unit we will first define terms, expressions, and equations. In the remaining units in this book we will review how to work with algebraic expressions, solve equations, and how to construct algebraic equations that describe a relationship. We will also introduce the notation used in algebra as we move through this unit.

(http://cstl.syr.edu/fipse/algebra/unit1/algebra.htm)

[youngtay]

Hi, please help


The average monthly salary of Hui Hui and her colleagues is S$4,300.00. Hui Hui earns S$4,700 each month and the average monthly salary of her colleagues is S$4,200.00. How many colleagues does she have?

TIA

[Mathmaniac]

youngtay:

Hi, please help


The average monthly salary of Hui Hui and her colleagues is S$4,300.00. Hui Hui earns S$4,700 each month and the average monthly salary of her colleagues is S$4,200.00. How many colleagues does she have?

TIA

Hui Hui earns $4,700-$4,200 = $500 more than an average colleague.

When she is added, average salary increases by $4,300-$4,200 = $100.

Total number of people = 500/100 = 5

Number of colleagues = 5-1 = 4

[youngtay]

Hi, Mathmaniac


Thanks

[Muffins]

A wrord of caution, Just4good,


If you post your comments immediately one after another, with the same words in them i.e. \"Algebra? What's that? :? :? :? Look's hard. Rather :stupid: than answer the question. (Just Kidding)\"

Chief might ban you for trolling the portal...... :slapshead:

[usaik]

Hi,


I need help on the following question.

Estimate the value of 372 ÷ 4

The answer is 360 ÷ 4. So 372 ÷ 4 is about 90. But how do one estimate 372 to be 360. What is the working to show that 372 can be estimated to be 360?

[Modelmatics]

Hi usaik,


To estimate means that we do not need to perform any calculation/working. You can explain to your kid that when we estimate, we want a rough answer quickly, thus we do some quick and convenient mental calculation.

When we perform addition or subtraction estimation, we usually approximate to the nearest tens, hundreds, thousands, etc. However, when we perform multiplication and division estimation, we make use of convenient numbers, i.e., the multiples of numbers/multiplication tables.

For primary kids, they are only required to learn up to 10 times tables. Hence, when they estimate, they should use 2 digits multiples which can be found in the 1 to 10 times table (i.e., 1 x 1 all the way to 10 x 10).

For this question, the first 2 digits are "37" (from the number "372"), thus we use the multiple of "4" closest to "37" which is 36. Therefore, we round it up to "360" making very easy to perform a quick mental calculation, i.e., 36 ÷ 4 = 9, thus 360 ÷ 4 = 90.

For PSLE, the kid’s answer should look like this:

372 ÷ 4 =(here should use "approximately equal to" sign) 360 ÷ 4 = 90

[usaik]

Hi Modelmatics,

Your explanation is extremely clear and hit on the nails those things which I couldn't explan to my kid. :thankyou: