If $a=0.421$ and $b=54.3$ complete the operation below:
$a+a+b$

is $y=2.5$ a solution to the following equation?

$3-y=6.8+y$

Add, then estimate to see if your answer is reasonable.

$23.16+15.25$

Add, then estimate to see if your answer is reasonable.

$186.79+7.548$

If $x=3.14$ and $y=12.7$ complete the operation below:

$x+y$

Subtract, then estimate to see if your answer is reasonable.

$25.96-14.25$

Subtract, then estimate to see if your answer is reasonable.

$7.548-18.609$

Add, then estimate to see if your answer is reasonable.

$-8.4+3.7$

Is $p=4.6$ a solution to the following equation?

$p+3.8=8.4$