How to use the CMSA mental math documents for practice

Here are all our newly updated Excell documents for CMSA mental calculations practice. Use F9 to generate new problems.

And here are all our newly updated Excell documents for practicing the CMSA optional mental calculations events:

The instructions on this page will help you use our mental math Excell sheets efficiently for practice. Or if you’re participating in our Honorary Mental Math Challenge, those same instructions will help considerably speed up the correction process. The process will work for any .xlsx or .doc documents presented.

As you may have seen, all our .xlsx (Excell) and .doc documents come in two versions: the regular versions and the “with answers” versions.

Here’s a secret: The regular versions of those documents also include the answers to all problems. It’s just that those answers are hidden from view.

Here’s how you can take advantage of that fact to speed up the correction process. It may seem like many steps, but that’s just because I wanted to be extra clear and precise. The whole process is actually quite fast and simple.

Step 1: Open one of those .doc or .xlsx document where the answers aren’t visible.

That’s pretty self-explanatory. Here’s we’ll open the division .xlsx document just for this example. Please note that the process would be exactly the same if we were to use a .doc document instead.

Step 2: Write down your answers in one of the two lines below each problem.

Here I’ll attempt to correctly calculate the first 5 problems. Maybe I’ll make one mistake.

Step 3: Use the mouse to select a block big enough to include at least all the problems you answered. Or just select the whole document.

Step 4: Change the color of the text to black (or to some other color).

This will make visible all the previously hidden answers. [Note that for some other types of documents, the answers may not appear underneath each problem but instead on another column on the right. You won’t miss them as long as you make sure to select a large enough block.]

Step 5: Check to see if your answers are correct.

Here I added a red circle around that one mistake I made. Remember that for divisions, when necessary you need to add a dot or a coma and the correct next 2 digits. And remember that for those 2 digits past the comma, we’ll accept either the straight non-rounded up or down answer, or when applicable the correctly rounded up or down answer. For 469 divided by 8 above, we can accept the 58.62 that I wrote, but we could also have accepted 58.63 (a correctly rounded up answer).

That’s it!

Hopefully that was clear enough and hopefully you won’t have any more problems. But just in case, I tried to anticipate and solve some possible technical difficulties some of you may end up experiencing.


Some potential technical problems you may experience:

Possible problem: “The numeric keypad on my keyboard isn’t working.”

Possible solution: Just find the “Num Lock” key and press it.

By the way, I hope you do have a numeric keypad on your keyboard. Some smaller laptops don’t have one, and that makes it much harder to be fast while typing down numbers. It’s possible to buy some external numeric keypad for 15 or 25 dollars. Whole new keyboards can also sometimes be found for the same price.


Possible problem: “The format is badly designed for printing.”

Possible solution: The format is fine on my computer, but it’s possible that it won’t be on yours. That may be because those documents were created using a clone of Microsoft Excell. If you’re printing, use the “print preview” option to make sure everything looks fine before. If it doesn’t, the problems should be minor enough (one row of problems appearing out of the printing area for example). I can’t offer a universal solution to everyone, but hopefully a few minor tweaks here and there should be enough to fix the problems. Maybe try just deleting the sets of problems that appear out of the printing area? Adjust the printing area? Delete some useless empty spaces? Adjust the font size to make them a little smaller?


Possible problem: “Hitting the F9 key doesn’t generate new problems.”

Possible solution: On many modern laptops, the F1-F12 keys have two possible sets of functions. If hitting F9 doesn’t generate new problems, they probably aren’t set to their classic functions. This article explains different ways you can change this.

Other possible solution: In Excell or in whatever software you’re using, you can certainly find a “Calculate Now” or “Recalculate Workbook” option that will serve the same function as the F9 key. You should be able to find it in the “Formulas” tab and then in the “Calculation Options” group. If you need more info, this article may help.


Possible problem: “All the problems in the document change every time I write down something.”

Solution: Normally this shouldn’t happen in any of the latest versions of the docs we provided, but if it does, you will need to find an option called “Automatic Calculation” and set it to “Manual”. This article explains how you can do in Microsoft Excell. If you’re using some other software, you’ll have to do some Googling to find how you can get to the same results. It shouldn’t be too complicated.