# Lesson Worksheet: Part–Whole Bar Models: Numbers up to 100

In this worksheet, we will practice solving one-step addition and subtraction problems with numbers up to 100 by drawing a part–whole bar model.

**Q1: **

Emma is trying to solve this word problem:

There were 41 birds in a tree. 15 of them flew away. How many birds are in the tree now? Emma said the answer was . What did she do wrong? What is the correct answer?

- AShe added when she should not have. The answer is 41.
- BShe added when she should have subtracted. The answer is .
- CShe added when she should have subtracted. The answer is .
- DShe made a mistake in the addition. The answer is .
- EShe added when she should have subtracted. The answer is .

**Q2: **

Ethan and Elizabeth were building houses out of blocks. Ethan used 36 blocks. Elizabeth used 51 blocks.

Is the number of blocks they both used bigger or smaller than the numbers in the question?

- ABigger
- BSmaller

Do you need to add or subtract to find the answer?

- ASubtract
- BAdd

Find out how many blocks they used.

**Q3: **

Benjamin has 62 blocks to build with. He used 29 blocks to build one house. He wants to build a second house with the leftover blocks.

Is the number of leftover blocks bigger or smaller than 62?

- Asmaller
- Bbigger

Do you need to add or subtact to find how many blocks he has left to build the second house?

- Asubtract
- Badd

How many blocks are left to build the second house?

**Q4: **

James is trying to solve this word problem:

There were 37 fish in a pool at the bottom of a waterfall. 12 fish swam down the waterfall into the pool. How many fish are in the pool now?

James said the answer was . What did he do wrong? What is the correct answer?

- AHe subtracted when he should have added. The answer is .
- BHe made a mistake in subtracting. The answer is .
- CHe subtracted when he should have added. The answer is .
- DHe subtracted when he should have added. The answer is .
- EHe subtracted when he should not have. The answer is 12.

**Q5: **

Anthony and Matthew were both playing a video game. At the beginning of the day, Anthony was at level 36 and Matthew was at level 26. During the day, Anthony moved up 16 levels and Matthew moved up 12 levels. Find the equation that shows the level Anthony reached.

- A
- B
- C
- D
- E

**Q6: **

On Wednesday, 23 boys and 55 girls went to the library. How many children went to the library on Wednesday?

**Q7: **

There are two buses. One has 46 tourists, and the other has 27 tourists. How many tourists are there in total?

**Q8: **

Subtract 30 from 50 to finish this part-part-whole picture.

**Q9: **

Ethan and Mia are making a bridge out of blocks. They choose 23 green blocks and 30 red blocks. How many blocks do they use altogether?

**Q10: **

One bag has 61 balls, and we add 9 more. How many balls do we have in the bag?