Subtract the wrong answer from the correct answer. If there is a minus sign, ignore it.
Divide this amount by the correct answer.
Turn this last value into a percentage by multiplying by 100 and adding a "%" sign.
For example, you guess that the answer should be 157 but the correct answer is 180:
180 - 157 = 23
23 ÷ 180 = 0.128 (approximately)
Percent error = 12.8%.
Another example: you guess that the answer should be 203 but the correct answer is 180:
180 - 203 = -23 ---> 23
23 ÷ 180 = 0.128 (approximately)
Percent error = 12.8%.
Subtract the wrong answer from the correct answer. If there is a minus sign, ignore it.
Divide this amount by the correct answer.
Turn this last value into a percentage by multiplying by 100 and adding a "%" sign.
For example, you guess that the answer should be 157 but the correct answer is 180:
180 - 157 = 23
23 ÷ 180 = 0.128 (approximately)
Percent error = 12.8%.
Another example: you guess that the answer should be 203 but the correct answer is 180:
180 - 203 = -23 ---> 23
23 ÷ 180 = 0.128 (approximately)
Percent error = 12.8%.