10.2 Signed numbers

$\text{6}+\text{1}$

$2+(-8)$

$-7+5$

$-10-(+3)$

$-1-(-8)$

$\text{0}+(-11)$

8

17

-6

-15

-(-1)

$-[-(-7\left)\right]$

Suppose $a$ is a positive number. Is $-a$ positive or negative?

Suppose $a$ is a negative number. Is $-a$ positive or negative?

Suppose we do not know the sign of the number $k$ . Is $-k$ positive, negative, or do we not know?

A number is denoted as positive if it is directly preceded by .

A number is denoted as negative if it is directly preceded by .

$-7$

$-5$

$\text{15}$

11

$-\left(-1\right)$

$-\left(-5\right)$

$5+3$

$3+8$

$\text{15}+\left(-3\right)$

$1+\left(-9\right)$

$-7-\left(-2\right)$

$0-\left(-\text{12}\right)$

$-\left(-2\right)$

$-\left(-\text{16}\right)$

$-\left[-\left(-8\right)\right]$

$-\left[-\left(-\text{20}\right)\right]$

$7-\left(-3\right)$

$6-\left(-4\right)$

( [link] ) Find the quotient; $8÷\text{27}$ .

( [link] ) Solve the proportion: $\frac{5}{9}=\frac{\text{60}}{x}$

( [link] ) Use the method of rounding to estimate the sum: $\text{5829}+\text{8767}$

( [link] ) Use a unit fraction to convert 4 yd to feet.

( [link] ) Convert 25 cm to hm.