Problem 219 - Prealgebra

Question

In the following exercises, solve. Savings John wants to buy a laptop that costs \(\$ 840\) . He has \(\$ 685\) in his savings account. How much more does he need to save in order to buy the laptop?

Step-by-Step Solution

Answer

John needs to save $155 more.

Step 1: Understand the Problem

Identify what the problem is asking. John wants to buy a laptop costing \(840, and he already has \)685. Determine how much more John needs to save.

Step 2: Set Up the Equation

Use subtraction to find out how much more John needs. The equation is: Amount needed = Total cost - Savings.

Step 3: Perform the Calculation

Subtract the amount John has from the total cost of the laptop: \[ 840 - 685 = 155 \]

Step 4: Interpret the Result

The result of the subtraction tells us the additional amount John needs to save.

Key Concepts

basic arithmetic

In word problems, basic arithmetic is the foundation you build upon to find solutions. Arithmetic involves simple operations such as addition, subtraction, multiplication, and division. For example, if you are trying to figure out how much more money John needs to buy a laptop, you can use subtraction. Understanding arithmetic helps you break down complex problems into manageable steps. Practice makes perfect, so try solving various problems to get more comfortable with these concepts.

subtraction

Subtraction is one of the primary arithmetic operations, crucial for solving many word problems. In John's case, we use subtraction to find out how much more money he needs. We start with the total cost of the laptop and subtract the amount he already has in his savings. The equation looks like this: \[\text{Amount needed} = \text{Total cost} - \text{Savings}\] For John: \[\text{Amount needed} = 840 - 685 = 155\] This tells us that John needs to save an additional \$155\.

savings calculation

Savings calculations are essential when planning purchases or budgeting. To calculate how much more you need to save, subtract your current savings from your total goal. For John, this means identifying the cost of the laptop and his available savings. Then, perform the subtraction: \[\text{Additional savings needed} = \text{Cost of laptop} - \text{Current savings}\] Putting in the numbers: \[\text{Additional savings needed} = 840 - 685 = 155\] So, John needs to save \$155\ more to buy his laptop. Savings calculations help you understand how far you are from achieving your financial goals and plan accordingly.