# Multiplication Facts up to 20x20?/ The Core and Saxon

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I read last night in the sample of The Core the recommendation to learn the multiplication facts up to 20x20.

I had already decided to go past 12x12, but had not decided how far and have no idea what the best methods to do this are.

I had also decided to learn cubes and square roots and I don't know what else, but most of the things I have identified as slowing me down in upper level Saxon work are listed in the sample pages of The Core.

Any tips on memory work for those wanting to complete upper level Saxon quickly and accurately?

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Skip counting, maybe? Works for kids ;). Ime most of the benefit of memorizing these sorts of things is so you can spot patterns quickly, and skip counting ought to help with getting relevant patterns in your head.

I did squares up to 30x30 in school by reciting them in my head, doing mental calculations for whichever ones I forgot or wasn't sure of. I can still do most of it today - the only ones I have problems with are the ones I always had problems with (the odd ones that I never saw outside my practice sessions). And my practice was really haphazard, but I've gotten a lot of mileage out of knowing common squares. I memorized powers of two just from using them a lot.

Anyway, my advice is to systematically go through it all once, figuring out the answers - make a nice master sheet - and then review frequently. You'll figure out real quick which ones are more commonly seen, because you'll learn them almost effortlessly. The weird ones will take lots more effort, because there is just about *no* reinforcement outside of your review sessions (and might not really be worth the effort).

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You could also go the Charlotte Mason approach, and just use your pretty master sheet as a cheat sheet, looking up anything you can't remember as you are doing your problem sets, repeating each one you have to look up a few times to try and fix it in your head. You ought to get most of the commonly used ones memorized with little effort that way, and there isn't much call to spend lots of effort on little-used ones unless you are big on completeness for completeness's sake ;).

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I don't know much about Charlotte Mason style math. I guess I need to do some reading.

A cheat sheet :-) I should have thought of that :-0 Duh! Sigh!

I am truly thankful for this board!

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I read last night in the sample of The Core the recommendation to learn the multiplication facts up to 20x20.
What is the basis for this recommendation? IMHO, the time and energy required would be better spent on practicing mental math techniques that can be generally applied. Knowing multiplication facts to 10x10 is essential. With practice, two-digit by two-digit multiplication can be done with good speed and accuracy having only these facts memorized, and not knowing any other "tricks."

Facts on which we do spend time include: perfect squares, perfect cubes, and powers of two so that my girls can recognize them instantly as such; common decimal to fraction conversions; skip counting at speed by 12's, 24's, and 15's; and, recognition of primes.

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I wouldn't add anything to Saxon--there's plenty of memorization already included. Perfect squares are already in the curriculum, along with a ton of other things. Are you doing the fact sheets? There's drill in 6/5 and 7/6 on all kinds of memory work. (Not sure what "upper level" you are on.) I find it's plenty.

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My first experience with Saxon was Algebra 1. I have barely caught a glance of the lower level books when the children of friends were using them. So I have no idea what the standard prep is supposed to be. I only know I spend way too much time figuring out things like 15x13 over and over again and too often making a silly mistake in basic math, that makes the whole problem wrong.

I had been reviewing with Algebra 2, earlier last fall, and just realized I was wasting too much time. Instead of being a quick review, lessons were taking a long time.

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What is the basis for this recommendation? IMHO, the time and energy required would be better spent on practicing mental math techniques that can be generally applied. Knowing multiplication facts to 10x10 is essential. With practice, two-digit by two-digit multiplication can be done with good speed and accuracy having only these facts memorized, and not knowing any other "tricks."

Facts on which we do spend time include: perfect squares, perfect cubes, and powers of two so that my girls can recognize them instantly as such; common decimal to fraction conversions; skip counting at speed by 12's, 24's, and 15's; and, recognition of primes.

:iagree: From someone who has a math degree, but has not memorized above 12x12. I'm a big fan of mental math strategies.

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I only ask my son to do 9x9. that is how I was taught when I was little (I was raised in Taiwan, One of the best country in Math) I see very little reason to go beyond it. My son can relate 12's just as fast using a little addition. I will have him memerize up to 12^2 to 20^2. but not now. I didn't do that until algebra. My theory of math is the less memorization, the better

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