Solve Integer Addition: (+71) + (-18) Step by Step

Q: Why don't I just add 71 and 18 to get 89?

Because the signs are different! When you have a positive and negative number, you're actually moving in opposite directions. Think of it as: start at +71, then move 18 steps backward to get 53.

Q: How do I remember which absolute value to subtract from which?

Always subtract the smaller absolute value from the larger one. Here: $ |71| = 71 $ and $ |18| = 18 $, so calculate $ 71 - 18 = 53 $.

Q: How do I know if my answer should be positive or negative?

The final answer takes the sign of the number with the larger absolute value. Since 71 is larger than 18 and 71 is positive, the answer is positive: +53.

Q: What if the numbers had the same absolute value?

If you had something like $ (+15) + (-15) $, the absolute values are equal, so you get $ 15 - 15 = 0 $. The answer would be zero!

Q: Can I use a number line to check my work?

Start at +71 on the number lineMove 18 units to the left (because you're adding -18)You land on +53, confirming your answer!

Integer Addition with Opposite Signs

$(+71)+(-18)=$

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Understand the problem

$(+71)+(-18)=$

Step-by-step solution

To solve this problem, we'll follow these steps:

Calculate the absolute values of the numbers: $|+71| = 71$ and $|-18| = 18$ .
Subtract the smaller absolute value from the larger one: $71 - 18 = 53$ .
Determine the sign of the result by using the sign of the number with the larger absolute value. Here, $71$ is larger and positive, so the result is positive.

Now, let's go through the calculations:
Step 1: Calculate the absolute difference $71 - 18 = 53$ .
Step 2: The number with the larger absolute value is $71$ , which is positive. Thus, the result is also positive.

Therefore, the solution to the problem is $53$ .

Final Answer

$53$

Key Points to Remember

Essential concepts to master this topic

Rule: When signs differ, subtract smaller absolute value from larger
Technique: Find $|71| - |18| = 71 - 18 = 53$
Check: Use number line: start at 71, move 18 left gives 53 ✓

Common Mistakes

Avoid these frequent errors

Adding absolute values instead of subtracting
Don't add 71 + 18 = 89 when signs are different! This ignores the negative sign and gives the wrong operation. Always subtract the smaller absolute value from the larger when signs are opposite.

Practice Quiz

Test your knowledge with interactive questions

a is negative number.

b is negative number.

What is the sum of a+b?

FAQ

Everything you need to know about this question

Why don't I just add 71 and 18 to get 89?

Because the signs are different! When you have a positive and negative number, you're actually moving in opposite directions. Think of it as: start at +71, then move 18 steps backward to get 53.

How do I remember which absolute value to subtract from which?

Always subtract the smaller absolute value from the larger one. Here: $|71| = 71$ and $|18| = 18$ , so calculate $71 - 18 = 53$ .

How do I know if my answer should be positive or negative?

The final answer takes the sign of the number with the larger absolute value. Since 71 is larger than 18 and 71 is positive, the answer is positive: +53.

What if the numbers had the same absolute value?

If you had something like $(+15) + (-15)$ , the absolute values are equal, so you get $15 - 15 = 0$ . The answer would be zero!

Can I use a number line to check my work?

Start at +71 on the number line
Move 18 units to the left (because you're adding -18)
You land on +53, confirming your answer!

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