Question

Error Analysis: Describe and correct the error in using a number line to find the sum of 2 and 5.

Short answer

Answer is +7.

Step-by-step solution

Explanation: How to add or subtract the integers.

To add two numbers with the same sign, first add the two numbers ignoring the sign and then put their common sign before the answer.

To add two numbers with the opposite sign, ignore their signs and subtract the smaller number from the bigger number. Then put the sign of the bigger number before the answer.

What is a number line. 

A number line is defined as the pictorial representation of numbers such as fractions, integers and whole numbers laid out evenly on a straight horizontal line. A number line can be used as a tool for comparing and ordering numbers and also performing operations such as addition and subtraction.

How do you use a number line to find the sum. 

Use a number line to find the sum: 2 and 5 

In the question it is given:

By mistake, locate the first integer as negative 2 and moved left to 5 units from the location of – 2.

2 and 5 both are positive; we need to move 5 units to the right from the location 2.

In correct manner on the number line and locate the first integer 2, then move 5(2^nd integer) units to the right from the location of 2. The answer will be the point you end on.

Evaluate: 2 + 5 = + 7