Error Repair Answer Key
About This Worksheet
This worksheet asks students to find and fix mistakes in problems involving powers of ten. Each example shows an incorrect answer, and students must explain what went wrong before writing the correct result. For example, 104 does not equal 1,000 because four factors of 10 produce 10,000. Error analysis is useful because it helps students understand the rule more deeply instead of only practicing correct examples.
Curriculum and Grade Alignment
This worksheet is written for fifth-grade math and reinforces CCSS.MATH.CONTENT.5.NBT.A.2. Students should already understand powers of ten, place-value shifts, and basic multiplication or division by 10, 100, and 1,000. The next step is explaining mathematical reasoning and checking whether solutions make sense. This activity strengthens both computation and the ability to communicate why an answer is correct or incorrect.
Student Tasks
On this worksheet, students will read eight incorrect solutions involving exponents, multiplication, and division by powers of ten. They must identify the mistake, briefly explain the error, and then write the correct answer. The examples include whole numbers and decimals, so students review several different ways powers of ten can appear. At the bottom, they complete a repair rule explaining what the exponent means in a power of ten.
Common Challenges
Some students may correct the answer without explaining what caused the mistake. Others may repeat the same incorrect rule if they are unsure how exponents and place value are connected. Decimal examples may also lead children to move digits in the wrong direction or by the wrong number of places. Teachers can help by asking students to state the rule first and then use that rule to show exactly where the original solution went wrong.
Teaching Tips
This worksheet is especially useful after students have had several days of practice with powers of ten. Teachers can use one incorrect example as a whole-class discussion and ask students to defend different possible corrections. At home, parents can have children play “math teacher” and explain the mistake as if they were helping another student. That approach can make the explanation part feel more natural and help reveal whether the child truly understands the rule.
Worksheet Features
The page contains eight boxed error-analysis problems with room for students to explain and correct each one. The mistakes cover several common trouble areas, including exponent meaning, multiplication, division, and decimal place value. A final repair rule gives students another chance to state the big idea behind powers of ten. The worksheet works well for review, small-group instruction, test preparation, or checking for misconceptions.