Post 2 Multiplying and Dividing Numbers and special note on ZERO.
- 4 times 5 = -20 50 divided by -10 = - 5
(- 8) 9 =-72
If multiplying or dividing by one positive number and one negative then the answer is negative.
- 4(- 8) = +32 or 32 (-7)(- 6) = +42 or 42
-18 divided by - 3 = 6
If multiplying or dividing by a negative number and another negative then the answer is positive.
+4(+ 8) =+32
You know a positive number multiplied or divided by another positive number yields a positive answer.
HOW to write a Multiply in Algebra!In algebra we do NOT use the x or the dot for multiply.
We write the numbers next to each other; some times we use parentheses.
3(6) or (3)(6) means multiply 3 and 6.
You must use only two of the numbers at a time to determine their sign.Try these examples:
A. -6(-7)(-4) = +42(-4) = - 168. The -6 times the -7 gives + 42. Then multiply by the -4.
B. (-4)6(-2) = -24(-2) = +48 or 48. The -4 times the 6 gives -24. Then multiply by the -2.
The rules for deciding the sign of the answer for multiplying and dividing are the same.
The / symbol means divide by or is the fraction bar.
It is also the divide key on the calculator.
which ones are less than 1 whole? 5/8 or 8/5. And 9/11 or 11/9?
And 14/7 or 7/14?DO YOU KNOW?
5/8 means 5 divided by 8.This should give you a decimal number that is less than 1 whole if you complete the division.
Do NOT confuse it with 8 divided by 5 or also called 8-fifths.
This is more than 1 whole. It is 1 and 3/5.Be sure you know which "way" to divide.
Do the division for the 5/8 and send me your answer in an email
Click: Susan O. Johnsey .
WHAT ABOUT ZERO in division? Zero is well understood with adding, subtracting and multiplying. But it is a bit peculiar, some would say, when it comes to division.
0/-4 = 0
Division by zero and Division into zero are quite different.
A common fraction that most students know is 4/5,
that is, 4-fifths. 4/5 means 4 divided by 5 .
Will the division give you a number larger than 1 or smaller than 1??
Can you read these fractions? Watch out!!6/5 is read "6-fifths" 5/5 is read "5-fifths" and equals 1 whole 5/4 is read "5-fourths".
OK? Keep going please:5/3 is read_______ 5/2 is read_________ 5/1 is read__________
5/3 is read 5-thirds 5/2 is read 5-halves 5/1 is read 5 wholes
5/0 is read_______ oops what did you say here? 5- zeroths!!!
what is that? there is no such fraction! And what about the 5/0?
5/0 is undefined (have you ever heard of 5-zeroths? I hope not! )
5/0 means 5 divided by 0.
There is not a simple number answer that can be given.
This is studied in Calculus so I will tell you for now to just know division BY zero is undefined. Do not confuse it with division into zero. 0/4 = 0
0 divided by 3 (zero-thirds) is 0,
but 3 divided by 0 (that is 3-zeroths) is undefined.