Find-the-error worksheets by skill

stepcheck has 18 skills for grades 2 to 7. Each one plants realistic mistakes, each named after the misconception behind it, in worked solutions that your students check. Open a skill to see a sample sheet and its answer key, or go straight to the generator.

Grade	Skill	Mistakes it plants	Standard
2	2-digit addition with regrouping	Forgot to regroup; Wrote the whole ones sum	2.NBT.B.5
2	2-digit subtraction with regrouping	Subtracted the smaller digit from the larger; Regrouped but did not take the ten away	2.NBT.B.5
3	3-digit addition with regrouping	Forgot to regroup; Wrote the whole column sum	3.NBT.A.2
3	Rounding to the nearest 10, 100 or 1,000	Looked at the wrong digit; Rounded 5 down; Cut off the digits instead of rounding	3.NBT.A.1, 4.NBT.A.3
3	Subtraction across zeros	Subtracted the smaller digit from the larger; Left the zero as 10 after regrouping through it	3.NBT.A.2, 4.NBT.B.4
4	2-digit by 2-digit multiplication	Forgot the placeholder zero; Added the carried digit before multiplying; Multiplied only tens by tens and ones by ones	4.NBT.B.5, 5.NBT.B.5
4	Comparing decimals	Thought more digits means a bigger number; Thought tenths always beat hundredths	4.NF.C.7, 5.NBT.A.3b
4	Multiplying a fraction by a whole number	Multiplied the numerator and the denominator; Multiplied the denominator instead of the numerator	4.NF.B.4
5	Adding decimals	Lined up the last digits instead of the decimal points; Forgot to regroup across the decimal point	5.NBT.B.7
5	Adding fractions with unlike denominators	Added the numerators and the denominators; Changed the denominator but not the numerator	5.NF.A.1
5	Long division (zeros in the quotient, remainders)	Left out the zero in the quotient; Wrote the remainder as a decimal	4.NBT.B.6, 5.NBT.B.6
5	Multiplying decimals	Counted the decimal places of only one factor; Multiplied the whole parts and the decimal parts separately	5.NBT.B.7, 6.NS.B.3
6	One-step equations	Used the same operation instead of the inverse; Divided the wrong way round; Subtracted the coefficient instead of dividing	6.EE.B.7
6	Order of operations	Worked left to right, ignoring multiplication first; Added before subtracting; Read the exponent as multiplication	5.OA.A.1, 6.EE.A.2c
6	The distributive property	Multiplied only the first term; Lost the sign when multiplying by a negative	6.EE.A.3, 7.EE.A.1
7	Adding and subtracting integers	Subtracted a negative as if it were positive; Added the sizes when the signs are different; Kept the sign of the first number	7.NS.A.1
7	Multiplying and dividing integers	Said negative times negative is negative; Made the answer positive because there were negatives to cancel	7.NS.A.2
7	Two-step equations	Divided only one side's term; Used the wrong inverse operation on the constant	7.EE.B.4a

Last updated 2026-10-02.