Singapore - Multiplication & Other Question

[melissamomof3girls]

Did you add any helps for your child to memorize multiplication? I have been letting my girls use a table and hoping the repetitively looking at it will help them memorize.

Also, what if it seems like the girls aren't getting the mental mastery? My older two are in 2B and it just seems I couldn't get them to understand the concept of breaking down 6 + 15. I think honestly I have been struggling to teach it well. I have always loved math so much and the mental aspect just came so easily to me and my girls dont' seem to be following that trend. I think we are having a bit of a disconnect. Any ideas?

Thanks!

[Larica]

Hi Melissa,

I don't have 2B to look at, so I don't know the intended approach, but maybe if you share how you are approaching 6 + 15 we can help with some suggestions?

Blessings,
Erica

[melissamomof3girls]

6+15 was just an example. I haven't been successful teaching them to do the math mentally. They rather prefer to put 15 on top, 6 on the bottom, add & carry-over. Does that make sense?

[pjdobro]

I did use Time Tales to help my dc memorize the multiplication facts. In retrospect though I don't know if it was necessary. It was fun though. I think using the multiplication facts repeatedly over time does the most good. We have a multiplication table on the wall in our school room that they still reference from time to time.

As far as the mental math, I would suggest just continue to present the lessons the Singapore way. They present the mental math along the way giving ways to think of it and practice it. Just continue the hands on activities that Carrie presents and follow the exercises in the workbook. If there is a concept that they don't seem to get, then redo that activity. I really think the mental math develops over time so don't worry too much about it. I do remember Singapore presenting the concept of adding up to a "10" so splitting the problem 15 + 6 into 15 + 5 +1. Have you done that yet? Unfortunately I can't remember where different concepts are presented and currently my earlier books are in the attic. I do remember that 2A is where they learn the concept of regrouping and learn to carry. So perhaps that is what is freshest in their mind and that is why they tend to go towards that. If you feel they need more practice with the concept of breaking a problem down mentally, you might try more practice with coins. In the 15 + 6 problem, you would use 1 dime, 2 nickels, and 1 penny. With that it is really easy to see how to group them quickly into 10s to make the problem simple mentally. The other thing I did when my dc were younger is we would sing , "everybody wants to be a 10" to the tune of everybody wants to be a cat. It's silly, but silly stuck with them. Those are a couple of thoughts, but again I wouldn't worry too much about it. The concepts will continue to come up and be reiterated many times along the way with Singapore so unless they aren't getting an activity/exercise when you are doing it, I wouldn't worry about it.

[melissamomof3girls]

Thank you Patty! GREAT ADVICE.

[Larica]

I agree with Patty that coins can really help kids "see/visualize" numbers as groups of smaller numbers, which really helps with mental math. Part of making 10s is being able to visualize 5's. For example, if the problem is 26 + 7, if you can visualize the 6 as 5 and 1, and the 7 as 5 and 2, then you can combine the two 5s to make an additional 10 with 1 + 2 remaining. So, the answer is 33. This is sometimes called the "two 5's strategy." You can also use coins (or other manipulatives) for "give and take" type strategies, especially with 9s and 8s. For example, if you have 39 + 6, take one from the 6 and give it to the 39, which makes the problem 40 + 5, which is easier to do mentally. If you have 78 + 5, take 2 from the 5 and give it to the 78 so you get 80 + 3 instead. These are some of the strategies that have helped my kids with mental math, along with some others. Perhaps they can help you too .

[my3sons]

I like to keep referencing the hands-on type activities HOD plans as helps later down the road if need be - like a little refresher. For addition, pjdobro gave a great example to use as a help, as did Larica. I don't have my guide here, but I know there are other great simple strategies in the plans. One simple one my dc use for a problem like 15 + 6 is to think...
5 + 6 is 11
11 is one 10 with 1 left
so now there is 1 ten plus the 1 ten that was already there = 2 tens (20) +1= 21

If a problem has 9's or 8's in it, you can make tens easily as well as a simple mental math strategy. For example, for 15 + 9 can be thought through like this...
I can take a 1 from 15 and put it with the 9
now the problem is 14 + 10
14 plus another 10 is 24

Or, if money... 98 cents + $1. 64 can be thought of like...
take 2 cents from $1.64 to give to the 98 cents
now the problem is $1 + $1.62
$1 + $1.62 = $2.62

However, I will say, there is a time and a place for mental math, and sometimes, dc just need to add with carrying to figure out the answer.

As far as multiplication, we found mastery of facts comes later with Singapore, but then it is more solid. Around 3A or even into 3B, it really seemed to start to stick. Skip counting is helpful for 2's, 3's, 4', 5's, and 10's. Teaching the 9's rule (which Singapore teaches anyway) is very helpful for the 9's. The 6's, 7's, 8's are toughest. It is important dc understand that 5 x 6 can be viewed as 6 x 5 and skip counted by 5 as this is easier. You can use skip counting for any of these harder numbers in this manner when paired with the 2's through 5's and 10's, and the 9's rule works for all of them, so really you are left with just a few toughies...
We sing these in a little made-up tune, it works because they are like 6, 6, and then hmm, hmm, 6; and 6 x EIGHT is forty-EIGHT!
6 x 6 is 36
6 x 8 is 48

7 x 8 just count up!... 5...6... 7... 8 When you see 7 x 8, think 5, 6, 7, 8... ahhh, it's 56!

Here's a rhyme we use for 8 x 8...
8 x 8 fell on the floor
pick them up
now there's 64!

We call these the toughies! My dc often count up one they know to solve these, and eventually, they just know they need to memorize the toughies!
6 x 7 = 42
7 x 7 = 49

That covers all of the facts! HTH!
In Christ,
Julie

[melissamomof3girls]

Fun Julie! Thank you for the tips. I think I need to print them off.