Question

Evaluate the expression. Justify each of your steps.

$1.29+18+21$

Short answer

The value of the expression is68.

Step-by-step solution

Step 1.  Order of operations

To evaluate any expression involving more than one operation, follow the below order of operations:

• First evaluate expressions inside grouping symbols like parentheses ( ) or brackets [ ].
• Evaluate the exponents.
• Perform Multiplication and division from left to right.
• Perform addition and subtraction from left to right.

Step 2.  Add from left to right

To evaluate the given expression$29+18+21$, first add the two numbers from left to right and then add the resulting number with the last number as shown below

$\begin{array}{c}29+18+21=\left(29+18\right)+21\\ =\left(47\right)+21\\ =47+21\end{array}$

Step 3.  Add the numbers

Now to simplify further, add the resulting number with the last number to get

$\begin{array}{c}29+18+21=47+21\\ =68\end{array}$

Thus, the value of the expression is 68.