Bar Model Word Problems: Find the Whole or Missing Part
Use bar models to make the relationship between a whole and its parts visible.
Teaching notes for parents and teachers
How to teach it
Label the whole and both parts with your student. Place the unknown in its box before choosing an operation.
Example to work through together
Use the model below as you explain the example. Have your student point to the quantities as you discuss them.
9 + 5 = 14
The whole is fourteen because both parts belong to it.
14 − 5 = 9
Nine books were there before the new books arrived.
Ask your student
Which two parts must fit together to make the whole?
If your student needs help
If the student puts the total in a part box, compare the labels with the quantities in the story.
Choosing and using the worksheet
These four questions include an unknown total, an unknown starting amount, and an unknown amount used, with numbers within twenty. They use part-whole bars, not comparison bars or multiplication models. The answer key fills the same blank and shows one suitable equation.
Make a practice set
Select the worksheet, answer key, or both. When both are selected, the answer key prints after the questions. Keep it separate if you want your student to work independently.
After your student finishes
Cover the equation and ask the child to explain what the whole and each part mean. Then cover the model and read the completed equation in the story. Agreement between the two is more useful than simply copying a diagram.
Word problemsFind the Starting Amount Word Problems
Work backward from a final total to find how many there were before.
6 problems · Answer key included
Word problemsFind the Missing Change Word Problems
Use the starting amount and what remains to find how many cents were spent.
6 problems · Answer key included
Word problemsChoose an Equation Word Problems
Decide whether addition or subtraction finds the missing quantity in the story.
4 problems · Answer key included
More about addition · Grade 1 worksheets
Grade 1 selected skill connection: 1.OA.A.1 (selected joining and taking-away relationships). See the Common Core standards for this grade. This worksheet does not cover every requirement in the standard.