Use a number line to find the sum.

13 + (– 3)

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.

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.

Draw the number line and locate the first integer 13, then move 3 (2^nd integer) units to the left from the location of 13. The answer will be the point you end on.

Evaluate: 13 + (– 3) = 13 – 3 = 10