Unit 4 - Multiplying and Dividing

Summary of Knowladge

In this investigation we will unmask the mystery behind negative numbers and we will learn to multiply and divide them. We will do it by applying real life examples in questions and problems to solve.

Vocabulary

Negative number: A number less than 0 and on a number line its located to the left of 0.


Absolute value: The absolute value of a number is the distance from 0 in a number line.


Positive number: A number greater than 0 and on a number line it is located on the right of 0.

Comutative property: Order of addition or multiplication that does not change the result.



Task Analysis

Multiplying a negative with a positive number


1. Take out the negative sign of the negative number.

2. Multiply the two factors

3.Put the negative sign to the final result

Multiplying negative numbers

1. Multiply the number as if it woulde be positive

2. If the amount of negative numbers is even the answer will be positive and if the number os negative numbers is odd the answer will be nagative.

Dividing negative numbers

1. Divide the number as if it was positive

2. If the amount of negative numbers is even the answer will be positive and if the number of negative numbers is odd the answer will be negative.

Example

-4*-2*-6*-8*-10= take out all the negative and fing the result signs so.....



4*2*6*8*10= 3840 because there are a odd amount of negative number the answer is negative



-4*-2*-6*-8*-10= -3840




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-8/-7/-1= croos out the negative sign. 8/7/1= 1.14 add negative sign to result because the amount of negative numbers are odd -1.14

OTHER HELPFUL SITES

Multiplying and Dividing » make test