Multiplying Signed Numbers: Multiplying Negative Numbers by Positive Numbers
This clip explains that, as when multiplying whole numbers, we can re-arrange the factors as much as we like when multiplying signed numbers. This enables us to solve multiplication problems in which the first factor is negative and the second posit...
Multiplying Signed Numbers: Multiplying Positive Numbers by Negative Numbers
This clip explains that, to multiply a positive number and a negative number, "
multiply their absolute values and use the negative sign."
Multiplying Signed Numbers: Multiplying Two Numbers With Different Signs
This clip explains that, to multiply two numbers of different signs, in whatever order, "
first, multiply their absolute values, and then use the negative sign. We don't care which comes first, the positive number or the negative number."
Multiplying Signed Numbers: Multiplying Negative Numbers by Negative Numbers
This clip explains that when a negative number is multiplied by another negative number, the product is actually positive.
Multiplying Signed Numbers: Second Exercise in Multiplying Signed Numbers
In this clip, the student utilizes rules taught in the lesson's previous clips to solve problems involving multiplication of signed numbers.
Factoring with (-1) to Rewrite a Polynomial
Factoring with negative numbers. Using negative one to change the signs of each term in an expression.
Multiplying Signed Numbers: Multiplication by Negative 1
This clip explains that, "sometimes, in mathematics you want to change the sign. Then it's useful to remember that to do it, just multiply by negative 1. Whatever the original sign might have been, the new one will be the opposite."
Signed Fractions: Summary: Signed Fractions
This clip summarizes signed fractions. It explains that negative fractions are just as useful as any other kind of negative number. The clip then re-visits the question of what exactly constitutes a negative fraction. It states that, if the numerato...
Signed Numbers: Comparing Absolute Values
This clip states that, "
if you look at the number line, you'll see that all negative numbers are less than all positive numbers." Nonetheless, the clip explains, "
even though negative 5 is less than positive 1, the absolute value of negative 5 i...
Signed Numbers: Absolute Value
Using a number line as a frame of reference, this clip explains that "
the absolute value of a number is its distance from the origin" So, negative 3 and positive 3 both have the same absolute value of 3. "We think of absolute value as an ordinary ...