Maria's Math News, August 2017

Hi again! School is starting for many of us... it can be exciting times!

In this edition:
  1. Math Mammoth news
  2. Giveaway: Science DVDs (grades 1-12)
  3. Word problems involving "four times as many as" (grades 4-7)
  4. A five-year old GOT the connection between addition and subtraction
  5. Multiplication algorithm and lattice multiplication (grades 4-6)
  6. What age do YOU think is old?

1. Math Mammoth news

I will be running a sale soon (in this month)! Stay tuned!

2. Giveaway: Science DVDs

I have something extra-special for you. I've arranged with Supercharged Science to give away...
  • 5 DVDs from their Ultimate Science Curriculum.
Each DVD is a complete study of one topic ranging from physics to biology to earth science. You can read more about the DVDs here. Winners get to pick which topic they want! (Worth $75 each).

CLICK this link now to access the free lesson and enter the giveaway

PLUS, as an added gift, you'll get a free hands-on science lesson video "How to create Instant Ice" that you can do today with stuff you already have at home.

Instant Ice

Aurora's science videos are top-notch! My girls have watched a bunch in the past and enjoyed them a lot. Now I'm starting my son on them and he's been fascinated because they are so hand-son. We recently made a sundial and a thermometer, and now he wants us to build an anemometer!

To get your free science lesson on "How to Create Instant Ice" and to register for this rather unique free giveaway, click this link:

3. Word problems involving "four times as many as"

Someone asked for help to explain the concepts of multiplicative word problems involving "as many as", like the ones below:
1) Haley had four times as many dollars as her sister. Together they had $60. How much money does Haley have?

2) Rachel had 5 times as many dollars as her sister, Nora. They had a total of $90. How much money did each of them have?

The BAR MODEL is an excellent tool for helping children understand what is going on in these types of word problems.

In (1), draw a bar for Haley and another for her sister. Divide Haley's bar into four parts, and make the other bar just one such part long.
Haley  |---|---|---|---|

Sister |---|

Now you will see that the TOTAL needs divided into FIVE equal parts — and from then on it is easy-peasy.

Additionally, you can use Thinking Blocks website to build such bar models INTERACTIVELY.

For problems like (1) and (2) above, choose the fourth model from the left (rightmost) in the top row that is bluish in color. Then click "Start modeling" button. Video tutorials exist also. This is not my site, but it's a very nice interactive tool for this concept!

4. A five-year old GOT the connection between addition and subtraction

I got this from a customer... how PRECIOUS!

Quoting Lydia's mom:
Lydia, who is not yet five years old, has just started the subtraction section of Math Mammoth 1A. She made an amazing discovery and wanted to tell you about it. A photo of her letter is attached, which a translation here.

"Dear Math People,
I found out
When you do a subtraction
It's adding
Did you know about that?
Lydia's mom also said that she feels Lydia is going to be so amazed when the workbook points this out a few pages from now!

5. Multiplication algorithm and lattice multiplication

This is a GOOD comparison between the standard multiplication algorithm and lattice multiplication!

The author even brings in the area model for multiplying multi-digit numbers (which I also show in Math Mammoth). The area model is of course only used to show students what is going on, based on place value — not to replace any algorithm.
In our desire for "efficiency," we lose transparency in the standard "long multiplication" algorithm.
Read it at

6. What age do YOU think is old?

I saw this in the IntMath Newsletter I subscribe to...
Here's an age equation that's pretty accurate:

OldAge = 10√NowAge

For example, if you are 45 now, then the equation gives you:

Oldage = 10 × √45 ≈ 67

So, to 45-year olds, 67 would seem old age. Or, if you're 35 now, we get:

Oldage = 10 × √35 ≈ 59

Similarly, when you're 16, old people are 40. When you're 50, old people are 70, and when you're 100, you know you're old!

Hat Tip to Murray from Intmath newsletter.

Yes, I know, we're all getting older... I felt I needed to update my image on the website and in the emails so here it is... cannot help it, I'm older now... good ways past 40. (You can calculate my age from this: the above formula gives that about 66-year-olds should seem old to me. :)) But there is one good thing that comes with age (usually), and that is, we've experienced more things in life, thus (hopefully) more wisdom.

Thanks for reading! :)

Feel free to forward this issue to a friend/colleague! Subscribe here.

Till next time,
Maria Miller
Math Mammoth freebies Math Mammoth on Facebook Newsletter Archives
Inspire4 Complete curriculum Placement tests