Homeschool Math Blog

Updated! There are some marbles in Box A and Box B. If 50 marbles from Box A and 25 from Box B are removed each time, there will be 600 marbles left in Box A when all marbles are removed from Box B. If 25 marbles from Box A and 50 marbles from Box B are removed each time, there will be 1800 marbles left in Box A when all marbles are removed from Box B. How many marbles are there in each box? Again, this is from Singapore and teachers have told students not to use algebra to solve this question. However, any form of heuristic tools are allowed to facilitate the students in solving the questions. I'd like to point out that I feel it's a good problem, but students might benefit from some "preparation". You could set up a preparation problem like this: Jar A has 100 marbles and jar B has 40 marbles. You will start removing marbles one by one from jar A, but by 2's from jar B. How many marbles are left in jar A when jar B is empty? What if you remove 2 marbles at a tim...

This question was set in one of the renowned primary school from Singapore. Given to me by "anonymous" to solve. Andy has $200 more than Peter. Andy gives 60% of his money to Peter. Peter then gives 25% of his money to Andy. In the end, Peter has $200 more than Andy. How much did Andy have at first? This is a great problem to solve with algebra. Why don't you try it first, before reading further? It sounds kind of interesting... first one guy has $200 more than the other, and in the end it's reversed. Solution: Let A be the initial amount Andy has, and P the initial amount Peter has. Then we know that A = P + 200. We're going to use that later, but for now I'm going to write it all in terms of A and P. Andy gives 60% of his money or 0.6A to Peter. Peter has now P + 0.6A. Andy has now 0.4A. Peter then gives 25% of his money to Andy. But this isn't 0.25P because Peter doesn't have P dollars anymore because Andy already gave him some. It's 0.25 (P + ...

This free lesson about mean and mode will get you a foretaste for my upcoming 5-A Complete Curriculum from the LightBlue Series. Download it here: Mean, Mode, and Bar Graphs - lesson for 5th grade. In the lesson I highlight the idea of mode versus mean (average) and when you can calculate the mean. Students also graph the data in bar graphs. I didn't include the median because elementary lessons on mean, median, and mode tend to concentrate on the calculation aspect only, and I didn't want that. In this lesson they at least get to graph the data and think if mean (average) is "calculable". So I decided to postpone the median till 6th grade... But here are some other lessons on these topics. Even with these you can see how much the actual calculations dominate the lessons. Using and Handling Data Simple explanations for finding mean, median, or mode. www.mathsisfun.com/probability Mode of a Set of Data A very simple and clear lesson with examples and interactive quiz ...

Mathematicians at UCLA have verified now the largest known prime number, 13 million digits long! It's a Mersenne prime , in the form 2 p − 1. This new prime is 2 43,112,609 − 1. (And no, you can't put it in your calculator and get an answer... ) Read the news story This kind of prime hunting requires a network of computers running together to do the massive amounts of calculations.

Considering the crisis taking place within U.S. financial institutions, it's a good reminder of how we MUST teach our kids how to work out the math with credit cards, mortgages, and any type of loans. Murray Bourne from squareCircleZ has taken this matter to heart and has written a good lesson about math that goes into taking a loan. He's also analyzed several misleading credit card ads and figured out the TRUE interest rate (which you find out after reading the fine print). First go here: Credit Cards - a simplified discussion on how banks make money on credit cards. This is a must read for all people (young or old) who even consider taking a credit. Then check these posts and warn your youngsters: Misleading Credit Card Advertising . This ad advertises "a attractive interest rate of 5% p.a." (p.a. means per annum or yearly interest rate), but has a "small" administration fee of 6%. And then check another misleading credit card ad which advertises a 0% ...

64 pages (of which 37 are lesson pages) Price: $2.50 download Buy at Kagi (PDF download) Sample pages (PDF) Contents and Introduction Shapes Right Angles Line Symmetry Perimeter Solids 1. Math Mammoth Early Geometry covers geometry topics for the early elementary grades (approximately grades 1-3). The first lessons in this book have to do with shapes - that is where geometry starts. Children learn the names of the common shapes, and also put several shapes together to form new ones , or divide an existing shape into new ones. They practice using a ruler to draw various shapes and are introduced to tilings. Next children learn the concepts of parallel lines and lines that are at a right angle (perpendicular lines). The book also has beginner lessons about symmetry, area, perimeter, and solids . After studying these early geometry lessons, you can continue the study of geometry with Math Mammoth Geometry 1 book . In it, children will learn to classify figures (dur...

Problem: If a:b = 1:3 and b:c = 3:4, find a:c. Two ratios are given, third is to be found. This is very very simple. The picture shows the two given ratios as blocks. We can see that a is one block and c is four blocks, so the ratio a:c is 1:4. You don't need an image for that, of course, since the original ratios are so easy. If a:b=1:3 and b:c=3:4, b being the same in both cases, we can write the ratio a:b:c as 1:3:4 right off. But what if the numbers weren't so friendly? What if it said this way: If a:b = 1:3 and b:c = 5:7, find a:c. This is solvable in various ways. I'll use equivalent ratios, in other words change the given ratios to equivalent ratios until we find ones where the b 's are the same. In the first ratio, 1:3, b is 3. In the other ratio, 5:7, it is 5. We can make those to be 15 by changing the ratios to equivalent ratios - which is done in an identical manner as changing fractions to equivalent fractions. 1:3 = 5:15 and 5:7 = 15:21. Now the ratio o...