find unknown numbers

Front

What is the process to find an unknown number in an equation?

Back

To find an unknown number, isolate the variable by performing inverse operations on both sides of the equation until the variable is alone.

Front

In the equation x + 7 = 10, what is the value of x?

Back

x = 3, because 10 - 7 = 3.

Front

How do you solve for an unknown number when it is added to a known number?

Back

Subtract the known number from the total to find the unknown number.

Front

What is the value of x in the equation x + 10 = 20?

Back

x = 10, because 20 - 10 = 10.

Front

In the equation 20 + y = 25, how do you find y?

Back

Subtract 20 from 25 to find y, so y = 5.

Front

What is the method to find an unknown number when it is subtracted from a known number?

Back

Add the unknown number to the result to find the original number.

Front

In the equation 9 - ? = 3, what is the unknown number?

Back

The unknown number is 6, because 9 - 6 = 3.

Front

How do you solve for an unknown number in the equation 16 - z = 12?

Back

Add z to both sides and then subtract 12 from 16 to find z, so z = 4.

Front

What is the inverse operation of addition?

Back

Subtraction.

Front

What is the inverse operation of subtraction?

Back

Addition.