Homeschool Math Blog

Laura had 24 clips more than Holly. After she gave 5 clips to Holly, Laura had twice as many clips as Holly. How many clips did Laura have left? This is from Singapore Challenging Word Problems book 3 (which they are now discontinuing, I heard). I found two ways to solve this using the bar diagrams. Solution 1. Notice that this is showing how I solved it initially, and at one point I had to adjust the length of the bar. Solution 2. In either case, once you get that x = 9 (the amount of clips Holly had in the beginning), it's easy to solve that Laura had 28 clips left after giving 5 to Holly. Algebraically: Initially Laura has L, Holly has L - 24. (Obviously you could also choose to use H and let Laura have H + 24.) Then Laura gives 5 to Holly, so now Laura has L - 5 and Holly has L - 24 + 5 which is L - 19. At this point Laura has double as many clips as Holly: L - 5 = 2(L - 19) and we can solve. L - 5 = 2L - 38 L = 33. Laura had 33 - 5 = 28 after she gave 5 to Holly. There are p...

This was asked of me as of today: Please solve this using the bar/block diagram method. My friends and I are stumped.... Desmond had 480 more oranges than pears. After selling half of his oranges and half of his pears, he had four times as many oranges as pears left. Find the number of pears he had at first. Thank you! This problem is from a Primary School Leaving Examination (PSLE) paper. PSLE is the final examination for primary school students in Singapore. So, you would expect to see these kind of problems in Singapore Math. My first attempt for solving this was like this: It shows the difference being 480. The red lines are halving the quantities of pears and oranges. But I quickly noticed this was way off. The amount of pears needed to be way less than the amount of oranges. My second attempt was like this: It was a little better, but half the pears looked more like 1/3 of the half the oranges. So the amount of pears needed to still be less. This is the final diagram that solves ...

I was asked this kind of curriculum question recently, and I thought I'd post it here too in case there are others who will get helped... I am torn between using Right Start, Singapore, or Math Mammoth with my daughter who is just starting her schooling journey. Do you have any insight to share that might help? Yes. If you are torn, try Singapore with Math Mammoth (if you can afford both). I've heard from people who use both and say they go well together, because Singapore is somewhat lacking in practice exercises. There are lots of folks who use two curricula for math. You would basically use one of them as your "spine" that you go by, and then for each topic, check the corresponding lesson in the other, if it has good explanations or problems. You wouldn't do all problems in both. Then, if you like RightStart, buy their math games book (but not the whole curriculum), which allows you to incorporate their games into your math lessons here and there.

Dave at MathNotations had an interesting ratio problem : In Virtual HS, the ratio of the number of juniors to seniors is 7:5. The ratio of (the number of) junior males to junior females is 3:2. The ratio of senior males to senior females is 4:3. What is the ratio of junior males to senior females? He asked if it can be solved using "Singapore" style bar model. I'm not sure if this is exactly how they'd do it, but this is how I'd do it... so here goes. After I made the diagrams, I soon saw that Dave's numbers are two awkward; the bar diagram drawing would get too messy because we'd need to divide it into too tiny parts to see anything. BUT... you probably know about the PROBLEM SOLVING STRATEGY called "solve an easier problem". My agenda is therefore: show how to solve a few related simple ratio problems using the bar diagram solve a variant of the original problem (with friendly numbers) solve the original problem. 1. Here's a bar diagram re...