Signed Numbers (Positive and Negative) - Examples, Exercises and Solutions

To determine the sign of the expression $(-16)\cdot(-5)$, we follow these logical steps:

• Step 1: Identify the signs of the numbers involved. Both numbers $(-16)$ and $(-5)$ are negative.
• Step 2: Apply the rule for multiplication of signed numbers: The product of two numbers with the same sign (both negative) is always positive.

Therefore, the sign of the result for the expression $(-16)\cdot(-5)$ is Positive.

It's important to remember: when we multiply a negative by a negative, the result is positive!

You can use this guide:

Let's remember the rule:

$(-x)\times(-x)=+x$

Therefore, the sign of the exercise result will be positive:

$-3\times-4=+12$

Let's recall the law:

$(-x)\times(-x)=+x$

Therefore, the sign of the exercise result will be positive:

$-2\times-\frac{1}{2}=+1$

When there is no minus or plus sign before the numbers, we usually assume that these are positive numbers as shown below:

(+1/4)*(+1/2)=

The dot in the middle represents multiplication:

So the question in other words is - what happens when we multiply two positive numbers together?

We know that two positive integers when multiplied result in a positive integer:

Therefore the answer is "positive".

Let's remember the rule:

$(+x)\times(-x)=-x$

Therefore, the sign of the exercise result will be negative:

$+5\times-\frac{1}{2}=-2\frac{1}{2}$

Let's remember the rule:

$(+x)\times(-x)=-x$

Therefore, the sign of the exercise result will be negative:

$-4\times+12=-48$

Remember the law:

$(+x)\times(-x)=-x$

For the sum of the angles of a triangle is always:

$-6\times+5=-30$

Let's remember the rule:

$(+x)\times(+x)=+x$

Therefore, the sign of the exercise result will be positive:

$+6\times+3=+18$

To solve the exercise you need to remember an important rule: Multiplying a positive number by a negative number results in a negative number.

$(−)×(+)=(−)$
Therefore, if we multiply negative 2 by 2 the result will be negative 4.

That is, the result is negative.

$+2\times-2=-4$

Remember the following law:

$(-x)\times(+x)=-x$

Let's think about which number we need to multiply by 2 to get 4:

$2\times2=4$

Now let's put the numbers together with the appropriate sign as written in the law above as follows:

$-2\times(+2)=-4$

Let's remember the law:

$(-x)\times(+x)=-x$

Let's think about which number we need to multiply by 6 to get 12:

$6\times2=12$

Now let's put the numbers together with the appropriate sign as written in the law above, as follows:

$-6\times(+2)=-12$

Remember the following law:

$(-x)\times(+x)=-x$

Let's think about which number we need to multiply by 3 to get 9:

$3\times3=9$

Now let's put the numbers together with the appropriate sign as written in the law above as follows:

$-3\times(+3)=-9$

Remember the following law:

$(-x)\times(+x)=-x$

Let's think about which number we need to multiply by 2 to get 8:

$2\times4=8$

Now let's put the numbers together with the appropriate sign as written in the law above as follows:

$+2\times(-4)=-8$

Let's remember the law:

$(-x)\times(+x)=-x$

Let's think about which number we need to multiply by 10 to get 100:

$10\times10=100$

Now let's put the numbers together with the appropriate sign as written in the law above as follows:

$+10\times(-10)=-100$