## Lesson 1: Integers. Lyrics and a Tricky Exercise (V)

October 8, 2011

Thanks for your translations. All of them were close to the right translation. There are two points:

Chips, in this context,  are some “little stones or plastic pieces” used to do calculations with integers in an intuitive way. Fried potatoes would not be appropriate.

To mix something up  means confundir con.

Here you are the lyrics and the  rap again

Integers Rap

I-N-T-E-G-E-R

When you know us

you’ll be a star.

I-N-T-E-G-E-R

This is the kind of numbers we are.

Positives, negatives and zero

Positives, negatives and zero

Get to know us

you’ll be a math hero

Use a number line and chips

When you do it so fast

And flips, and flips, and flips.

Multiplying and dividing use the rules

Don’t mix them up

Use the rules.

I-N-T-E-G-E-R

When you know us

you’ll be a star.

I-N-T-E-G-E-R

This is the kind of numbers we are.

Positives, negatives and zero

Positives, negatives and zero

Positives, negatives and zero

Positives, negatives and zero

Get to know us

you’ll be a math hero

Get to know us

you’ll be a math hero

Multiplying and dividing use the rules

Don’t mix them up

Use the rules.

### A tricky exercise

The product of H.C.F and L.C.M. of two numbers is 9072. If one of the numbers is 72, find the other number. Justify your answer.

### Your reward will be 0.5 extra points in this lesson grade

1. It’s impossible, because in the list common multiples of 72 appear three to the power of two and in the list common factor of 9072 appear three to the power of four.You need three to the power of four because in the H.C.F. you must colect the numbers with the lowest exponent.

2. -The number is 126.
-The product of HCF and LCM of two numbers is the same as the product of these two numbers. So I divide 9072 between 72 and get the result of 126.

3. 9072:72=126
Is 126, because if the multiplication of the HCF and LCM, is 9072,the other has to be the result of the division.
126:2=63
63:3=21
21:3=7
7:7=1

72:2=36
36:2=18
18:2=9
9:3=3
3:3=1

HCF= 18 LCM= 504 504.18=9072

4. Monica, i left a reply last monday, the day of the exam, and today i can´t find it. Do you know what happened?

5. Where is write the true answer?