Best way to teach subtraction without confusing son

[confusedinlondon]

My son is in year 2 and has problems with subtraction, I want to help him but don't want to confuse him. He sometimes misses out numbers when counting backwards, although if i ask him to count back 10 numbers from any give number he usually gets it right.
I am teaching him the same method they teach in school: count back in 10s then 1s
but in a few books they have suggested counting forward so 28 - 9 = start at 9 and count onto 28.
Is it advisable to start teaching him this method of counting forwards as he is being taught a different method in school and i don't want to confuse him.
because of covid the teacher isn't really open to meeting or speaking with parents.

Can he use a number line? So 28-9 he has to start on 28 the jump back 9 spaces. That’s how they teach it at my kids school.

but in a few books they have suggested counting forward so 28 - 9 = start at 9 and count onto 28.

That’s a useful strategy to have, if it’s adding one, then ten, then eight rather than counting on fingers.

The thing that will make the biggest difference is a fluent understanding of number bonds. Then he can quickly use the fact that 9 = 8 + 1 and 28 = 20 + 8 to subtract 8 from 28 to give 20 and subtract another one to give 19.

Number lines can be useful but really, it’s that quick recall or fast calculation of those number facts that makes the difference.

@Dinosaursdontgrowontrees

Can he use a number line? So 28-9 he has to start on 28 the jump back 9 spaces. That’s how they teach it at my kids school.

A blank number line? Yes he can use that but at school the do not provide a 100 square of a number line with numbers.

Placemarking for my DC definitely not myself 👀😂

@PurpleDaisies

but in a few books they have suggested counting forward so 28 - 9 = start at 9 and count onto 28.

That’s a useful strategy to have, if it’s adding one, then ten, then eight rather than counting on fingers.

The thing that will make the biggest difference is a fluent understanding of number bonds. Then he can quickly use the fact that 9 = 8 + 1 and 28 = 20 + 8 to subtract 8 from 28 to give 20 and subtract another one to give 19.

Number lines can be useful but really, it’s that quick recall or fast calculation of those number facts that makes the difference.

Every weekend I give him some arthritic sums to do . 9+6= 11+4= 8-5 = He can do these but needs to use his fingers - should he be doing these in his head?

By the end of year 2, children should have memorised their number bonds through to 20 and be able to do them in their heads. As long as he understands subtraction and addition conceptually he should be moving towards fluency with these number facts.

XtraMath is a good app for practicing this as is Hit the Button. Hit the Button is probably slight better for a child that gets anxious with being timed.

Have him use a number line with numbers and get a number square poster and hang it up some place he can see it all the time.

He also needs to be able to count forward and backward without missing a beat. It should be totally automatic. Count forward and backward to 100 everyday with him. The easiest way to incorporate this is to do it while he is brushing his teeth to time its been long enough. If you do forward in the morning and backwards at night, he'll know it be rote very quickly and won't stumble. Also, doing it while brushing teeth makes it feel like less of a chore!

Every weekend I give him some arthritic sums to do .
9+6=
11+4=
8-5 =
He can do these but needs to use his fingers - should he be doing these in his head?

It’s more the understanding that eight is made of 7 and 1, or 6 and 2, or 5 and 3, or double 4 without needing fingers.

These things are often best reinforced using objects, images, animations etc. There are some good free resources here...

numbersensemaths.com/

Schools should be moving away from teaching counting on fingers as the only strategy children have for performing calculations with addition and subtraction.

Agree that the best way is to help him understand how numbers can be made up. Give him counters or pennies or blocks or anything that he can use to visualise and ask him to work out three different ways to make 7 (eg 5+2, 6+1, 3+4). Repeat with different numbers. My DS started with blocks but quickly progressed to doing it in his head from there.

Hi op, I worked in year 2 last year. Being secure in number bonds 0-10 and 0-20 is key. Use lots of manipulatives as he will clearly see what's happening to the numbers. I would give the children the tools of counting forward as well, some children understand it a lot easier that way. Draw circles or lines to represent the ones and tens. If he isn't secure, just stick to ones at the moment. Also this year is different, the children missed 4 months of school, they are not doing year 2 sats this year, which is great.

Shut the Box is a fun game to play for number bonds.

He may not actually be understanding what the numbers mean physically. Then it’s hard to take away in an abstract way.
Use sweets if he is really hard to engage!
If not then Coloured counters are your friend.
Let him physically see what the numbers mean.
15- 5= 10
Do it with counters.
Then progress to a number line. Let him move his pencil down the number line to record each number taken away.
It’s an old fashioned method but it works.
My mother (retired head teacher in her nineties) says children need to understand the oneness of one, and the twoness of two etc before they can compute abstractly.

Good luck!

Ps thank you for your question, it has given my mother and I something to chat about. She gets so bored being confined indoors in these strange times.

I know it's old school, but I bought DS a wooden abacus!! Does exactly the same as a 100 square but is more visual!!

I should say I agree that before becoming fluent if the conceptual understanding isn’t there start with blocks.

A fun way to do this is set out for example 7 blocks and then he closes his eyes and you steal some. He counts how many are left and has to figure out how many you stole. You keep doing this until you’ve done every combination.

pennies or gummi bears or peas or other small objects.

sometimes something tangible to count helps at this stage.