LbQ’s partners White Rose Maths launched the month of Barvember in 2017 as a way to celebrate one of the most valuable visual representations in maths. With a range of problems set each day, the end solutions are not necessarily the challenge. Rather, the challenge is often the creation of the bar models themselves and the discussion about how to represent the mathematics at the core of often complex problems. Various solutions and models are shared on social media throughout November, stimulating debate and helping to embed core mathematical structures in a fun and engaging way.
Many of LbQ’s Question Sets contain bar models to help children to secure their understanding. Here, we pick out 5 of our favourite uses of bar models.
## Number 5: Measurements
In at number 5, one of the simplest bar models that helps to reinforce key relationships between various units of measurement.
### Question: Convert 4 km to metres.{: .center }
![alt text](/filestore/BlogImage/c1c1e60a-1180-4222-b6eb-9249792808cc/eb3e98c3-20e4-4cdf-9d4f-3e1e6ac8590ebarvember1.jpg ""){: .center }
Many of our [measurement Question Sets](https://www.lbq.org/search/mathematics/measurement?years=1,2,3,4,5,6&keywords=measurement&hide=true) contain these types of bar models alongside other representations.
## Number 4: Calculating with fractions
At number 4, we have bar models for word problems involving fractions. When presented in a word problem, children often fail to see the necessary steps. In level 2 of our Question Sets, we often provide basic bar models so that children can see what steps they need to take more effectively.
### Question: Mr Jones has 1 kg of sweets. He gives a quarter of the sweets to Alice and a fifth to Ben. How many grams of sweets does Mr Jones have left?{: .center }
![alt text](/filestore/BlogImage/c1c1e60a-1180-4222-b6eb-9249792808cc/c204ca57-2a4a-46da-a6c4-9bacc609910ebarvember2.jpg ""){: .center }
## Number 3: Calculating with Negative Numbers
A popular entry at number 3 is the use of a bar model to demonstrate how to find the difference between a negative integer and a positive integer. Children often struggle to comprehend why they should use addition when they see a minus symbol: the bar model clearly shows why addition is the correct strategy.
### Question: What is the difference between -15 and 7?{: .center }
![alt text](/filestore/BlogImage/c1c1e60a-1180-4222-b6eb-9249792808cc/dd669aac-0a10-4acc-ad6d-488e8121bd31barvember3.jpg ""){: .center }
## Number 2: Ratio and Percentages
Just missing out on top spot, the use of bar models for ratio and percentage problems is one of the most effective bar models. These simple bar models highlight to pupils the division step of finding a percentage or solving a ratio problem. With ratio in particular, pupils often fail to see the total number of parts that a given quantity needs to be divided into. Bar models such as the one below clearly illustrate that there are 9 total parts in the ratio 4 : 5, so they need to divide by 9 to find the size of each block.
### Question: The ratio of blue balls to red balls is 4 : 5. If there are 27 balls in total, how many red balls are there?{: .center }
![alt text](/filestore/BlogImage/c1c1e60a-1180-4222-b6eb-9249792808cc/89c157fa-293b-4c4e-a4cf-9d9f059ba7a4barvember4.jpg ""){: .center }
### Question: Calculate 10% of 96.{: .center }
![alt text](/filestore/BlogImage/c1c1e60a-1180-4222-b6eb-9249792808cc/2290c11e-116b-4675-900e-92f0cb6d4a4dbarvember5.jpg ""){: .center }
## Number 1: Solve problems with Two or More Unknowns
And finally, at number 1 is the use of comparison bar models to show how to solve some of the trickiest types of word problems. Pupils often struggle to solve problems with two or more unknowns (see the examples below). Using bar models, it becomes clear that they can subtract the differences from the total to find the smallest unknown. They can then use the given information to find the value of the other unknowns if required. As well as bar models, children are supported with targeted feedback to guide them and address any misconceptions.
### Question: Lindsay is 18 years older than Mark. If the total of their ages is 64, how old is Lindsay?{: .center }
![alt text](/filestore/BlogImage/c1c1e60a-1180-4222-b6eb-9249792808cc/c74be395-bae5-4d6a-9e35-a3a24b9924eabarvember6.jpg ""){: .center }
That's our top five bar model sets for you. Now it's time for you and your children to [get solving them](https://www.lbq.org/search/mathematics/measurement?years=1,2,3,4,5,6)! Keep an eye on our social media throughout Barvember for some more bar model fun!
Happy Barvember everybody!