# Error patterns

Solve the unanswered problems using the same pattern as the student. What misconeption(s) does the student have about place value?

## Carol

Adds all digits together for three digit problems. (11, 84, 16)

## Robert

Adds like multiplication. (134, 131)

## Mary

Adds left to right and carries to right. (789, 1112)

## James

Subtracts lower digit from higher digit in each place value. Most common error. (126, 255)

## George

Always regroups from tens. (265, 2112)

## Bobby

Reuses previous carries. (5528, 3970)

## Josephine

Add carry before multiplying. (500, 127)

## Jim

How many times does smaller digit go into larger digit? (213, 142)

## Ally

Brings down two digits instead of one. (32 r.2, 78 r.2

# Error patterns » extra practice

## Mike

Writes answer below digits. (108, 1117)

## Donna

Anything subtract zero is zero. (104, 530)

## Barbara ~

Regroups from hundreds if two regroupings are needed. (264, 187)

## Margaret

Regroups like base 10, not based on correct units. (3 yards and 2 feet, 1 quart and 3 cups)

## Sam

Always regroups highest place value, regroups from right, and 0 - N = 0. (153, 110)

## Cheryl

Left most times left most. Middle times middle. Last times last. (1243, 2081)

## Billy

Ignores carries. (95, 82)

## Anita

Brings down two digits instead of one. Tacks on zero for place value. (830, 520 r. 4)

## Winston

Writes quotient right to left (52, 68)