Karra's Scribe Post for November 4, 2010

2.2 - Text Book
Question: #16

Bella is more comfortable working with integers than with positive and negative decimal numbers. This is her way of understanding -4.3 + 2.5 .

-4.3 is -43/10 or -43 tenths

2.5 is 25/10 or 25 tenths

-43 tenths + 25 tenths is -18 tenths

-18 tenths is -18/10 or -1.8

So, -4.3 + 2.5 = 1.8

A ) Use Bella's method to determine 6.1 + (-3.9).

B) How could you modify Bella's method to determine 1.25 -3.46?

Kathleen's Scribepost for November 4, 2010

2.2

Question #12

A pelican dives vertically from a height of 3.8 m above the water. It then catches a fish 2.3 m underwater.

a) Write an expression using rational numbers to represent the length of the pelican's dive.

b) How long is the pelican's dive?

a) Answer will be a rational number or integer cause the question asked to write an expression using rational number.

3.8 - (-2.3)

3.8 is positive because it's above water and -2.3 is negative because the pelican went underwater.....like descending.

The answer is a positive because the subtrahend is much bigger than the minuend.

b) The pelican's dive is about 6.1 meters long.

Kisha's Scibepost for October 18th

Today in math class, Mr. Backe gave us a yellow booklet with decimal work sheets. He assigned pages 1 and 2. The first page is addition, and the second page is subtraction. You're not aloud to use your calculator. If you can't do one of the questions mentally, do it on graph paper. Make sure to line up the decimals!

64.1+62.2=126.3

73.08-37.98=35.1

We also made boxes on a big sheet of paper. One side looked like this:

On the other side of paper it looked like this:

For the next scribe I pick.... KRYSTAL!

Good luck... !

Homework

Make sure to have finished:

• Chapter Warm-up 2


• Get Ready (homework book)


• All SYK in 2.1


• Everything in 2.1 except extend.


• First two pages of the decimal worksheets!

Don't you just love math? :)