Homeschool Math Blog

Someone asked me about the BAR MODELS in the problem solving lessons in Math Mammoth grade 5. This person said that they had just completed every problem in the lesson Problem Solving with Bar Models 1, but her son is still having a hard time knowing how to make the bar model after reading the problem, and knowing what to do with the fractional part once it is figured out. She was wondering if there was something else for supplemental practice , and if she should look for mastery in this area at this point. MY ANSWER : I feel it would be good to achieve some degree of mastery at this point (in 5th grade). I suggest  using the website Thinking Blocks for additional practice, in particular the "Multiplication and Division" and "Fractions" subsections. Also, if the problem solving lessons are difficult, consider spreading out the study of these lessons in Math Mammoth by starting the child simultaneously on the next chapter. For example, one could s...

Someone asked me recently, I have had great success with the Grade 4 Light Blue Series with my twin daughters and we have been breezing through the curriculum. ... For the most part, they get how to find the fractional part but we did have some trouble on problems 4 on page 59 Worktext 4-B and problem 7 on page 60 in Worktext 4-B. They have to do with finding the total number of something when you are given a fractional part. I had a hard time teaching the concept of "working backwards" and was wondering if you have any additional resources or problems we could use to practice. Working backwards is of course perfectly FINE but I feel using the BAR MODEL is easier for children who have not worked through these kinds of problems before. The model shows them clearly HOW we "work backwards" to get the total. Here's an example from the previous page (page 58 in Math Mammoth 4-B ): This is the problem #4 they had trouble with One cold day, 1/8 of ...

I have 2 questions on fractions which I can't solve. There were 3/5 as many adults as children on a bus. At the next bus stop, 6 adults and 6 children boarded the bus. As a result, there were 2/3 as many adults as children on the bus. How many people were on the bus at first? A solution using bar diagrams (Singapore style): children |----|----|----|----|----| adults |----|----|----| Then we have: children |----|----|----|----|----| +6 adults |----|----|----| +6 Here look at the difference of children and adults. There are two "blocks" more children than adults. We know the number of adults is 2/3 of the number of children... therefore the DIFFERENCE of two blocks must be 1/3 of the children. Now look: children |----|----|----|----|----| +6 Two of those blocks is 1/3 of the total... the other two blocks is another 1/3 of the total... so |----| +6 or one block and 6 must be 1/3 of the total. This means the +6 must be one block. Or, one block = 6. This no...