Add up all the individual items.

Billy had \(\displaystyle \$20.00\). After buying the toy he had \(\displaystyle \$10.51\) left over:

 \(\displaystyle (20-9.49=10.51)\).

After buying the candy bar he then had \(\displaystyle \$9.26\) left for his piggy bank,

 \(\displaystyle (10.51-1.25=9.26)\).

In order to solve this problem, you must add all of the costs of school supplies together. This can be done through the following equation: 

\(\displaystyle 23.45+1.35+2.34+0.60 = 27.74\)

Therefore, the total amount that John spent on school supplies is \(\displaystyle \$27.74\). 

You must subtract the cost of the two purchases from the overall paycheck amount.

Begin by subtracting the shoe purchase from the total paycheck amount:

\(\displaystyle \$245.74-\$61.39 = \$184.35\)

Then, subtract the cost of the dress: 

\(\displaystyle \$184.35-\$15.29 = \$169.06\)

\(\displaystyle \$169.06\) is the amount of money Jenny has left from her paycheck on Monday.

The key word, "approximately," indicates that we must round each of these values. Let's round to the nearest tens place because each of our answer choices is rounded to the tens place.

Shoes cost $42.64. 

$42.64 rounded (down) to the nearest tens place is $40.

Pants cost $37.99.

$37.99 rounded (up) to the nearest tens place is $40.

A shirt costs $21.34.

$21.34 rounded (down) to the nearest tens place is $20.

Let's add up our estimated prices.

$40 + $40 + $20 =

$100.

Since we're looking for an approximate value, we need to round our numbers up. Adding the three items gives a total of $60.74, so at least $61 is needed - thus $61 is the correct answer.

The flat fee for the shoes will only be paid once since the shoes will be used for all four games.  The cost per game will be paid each time one game finishes and a new one is started.

To calculate her cost add the fee for the shoes and the fee for each game played.  That would be $8 (shoes) + $10.50 (game 1) + $10.50 (game 2) + $10.50 (game 3) + $10.50 (game 4) = $50 (total cost).

Laura had $50 with her so there was enough money and nothing left over when she left the bowling alley.

To solve this problem, one should round either to the tenths place, or to the nearest dollar. \(\displaystyle \small \$2.48\) can be rounded to \(\displaystyle \small \$2.50\), \(\displaystyle \small \$12.99\) to \(\displaystyle \small \$13.00\), \(\displaystyle \small \$5.99\) to \(\displaystyle \small \$6.00\), and \(\displaystyle \small \$.51\) to \(\displaystyle \small \$.50\). When one adds up the estimated costs, it yields about \(\displaystyle \small \$21.00\).

In this problem, the costs of the items can be rounded to either the nearest dollar, or the nearest ten cents. 

\(\displaystyle \$12.99\) and \(\displaystyle \$13.99\) can be rounded to \(\displaystyle \$13.00\) and \(\displaystyle \$14.00\), respectively. 

\(\displaystyle \$4.49\) can be rounded to \(\displaystyle \$4.50\), and \(\displaystyle \$.51\) can be rounded to \(\displaystyle \$.50\).

When the new, estimated costs of the items are added, the sum is \(\displaystyle \$32.00\), which is between \(\displaystyle 30\) and \(\displaystyle 35\) dollars.

First, add up all of the values:

\(\displaystyle \$12.99+\$6.99+\$8.99+\$4.37=\$33.34\)

Then, decide which of the answer choices approximates this value. Our answer is between \(\displaystyle \$30\) and \(\displaystyle \$35\).

Another way to solve this problem is to round the four values to their nearest whole numbers and then sum those rounded values:

\(\displaystyle \$12.99+\$6.99+\$8.99+\$4.37\approx \$13 +\$7+\$9+\$4=\$33\)