what is a number bond?

[Howstricks]

My 6 yo apparently knows his number bonds to 10 and his target is to learn them to 20. What on earth is a number bond?

1+9
2+8
3+7 etc

So basically learning the 'pairs'.

All the possible pairs of numbers that add up to a target number. Having rapid recall on them really helps with mental maths.

Number bonds to 20:

0+20
1+19
2+18
3+17
4+16
5+15
6+14
7+13
8+12
9+11
10+10
11+9

etc

Need to learn with instant recall as much as possible,

Thank you..that makes sense.

Can I just ask, would you therefore test them on all the ways to make 8 for example?

I think the emphasis is on quick recall of pairs of numbers (bonds) that add up to 10 or 20 as this helps with lots of mental maths strategies. There is less focus I think on number bonds with different totals eg 6, 8 , 14.

Less focus but still very important. When I teach children to add by counting on to the next multiple of 10, very many of them struggle because they don't know instantly that 8 is 3 add 5. So if we were doing 7 plus 8 their default is to count on in 1s. But it's much more efficient to do 7 plus 3 is 10 and then 5 more. It uses the bonds to 10 they've learnt, but if they can't break down the smaller number its very hard.

I got this on mumsnet 4 years ago. Sing to the tune of "Row Row Row Your Boat"

Nine and one, eight and two are the number bonds
Seven and three, six and four
And five and five are twins

Hi howstricks:

With numberbonds to 10 and to 20 - I'd just like to share the mistake we made.

With DD1 initially we just focused on all numbers making 10 (so as Nicknacks posted - 1+9, 2+8, etc..) and with 20 (all combinations making 20 - as Hulababy posted - 1+19, 2+18, etc...).

Now these are great and very important - BUT....

Don't forget all the one's between

all combinations to make 3, 4, 5, 6, 7, 8, 9 and all combinations to make 11, 12, 13, 14, 15, 16, 17, 18, 19.

Why - because knowing these combinations well - helps with additions totally >20 and ultimately helps with subtraction. (both in terms carrying over & borrowing).

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We found playing bond snap was a really useful way of learning this.

So start with 6 (for example). Take a normal deck of playing cards and take out all Aces (which =1 for this game), 2s, 3s, 4s and 5s. Shuffle them and put them all face down in one pile.

Take a white sheet and write a big 6 (your target number) and put the deck of cards you prepared next to this.

Flip the first card. Say it's a 2. So what +2 = 6?

First to shout out 4 win's the card.

The overall winner is the one with most cards at the end.

You can play this working through all combinations to make a total.

You can play this with a start number (say 6 again) - and whatever you flip over is added to 6. (you can add in 10s by making all face cards (King/ Queen/ Jack = 10 or later jazz it up by making King = 50, Queen = 30 and Jack = 20).

You can work on subtraction skills by playing that the flipped card is taken away from the target card or visa versa - the target card is taken away from the flip card (just make sure that the flip pile works with whichever version - so you aren't going into negative numbers).

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You can play snakes and ladders with more than one die - to work on bigger additions. Play it backwards to work on subtractions.

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You can play 21 (black jack) to work on all additions to 21 (actually over - but of course you lose if you go over 21).

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We found with DD1 although she absolutely knew her number bonds to 10 or 20 - she was so week in between that we had to almost go back to basics before she could cope with subtraction of one digit from 2 digits or even bigger numbers.

HTH

I had to ask dd's teacher the same thing a few years ago!

Good point Hogwash - I checked an on-line maths dictionary - and no number bond (or bond [number]) wasn't there.

But basically I think your comment raises a really crucial point (to teachers reading this out there):

PLEASE PLEASE don't just send a note saying parents work on x with your DCs this weekend. Give some examples and if it is a bit of a tricky concept - some explanation.

I realise that you know what you're talking about/ doing - but we don't always or, worse yet, we're so old we never heard of the term.

I've had this with number bonds
deconstructing (breaking numbers down into parts: hundreds, tens, units)

number line

100 square

chunking

• a lot of this was finally explained by a booklet on learning maths given to us in June of Y1. As one parent said in the feedback to the school - Why oh why didn't you give this to us at the start of the school year?

I vote to nominate pastsellbydate for an award for always giving great and lengthy advice in so many different situations in primary education.

Anyone want to second me?

What about it, MNHQ? Could you provide a crown icon beside her name or something?

Hogwash

Yes - I find these 'evenings' interesting events. In general I go along, if DH can look after the kids - but many parents either work shifts or can't get the childcare.

My old cynical self thinks - Hmmm... Is this about ticking the box - we held an evening to discuss X. and not about We as a school really really want to explain to parents what we're doing and how they can help.

Because if it is the second, why not have some of the teachers hanging about at the 'evening' - show a film or play games with children in another classroom?

Yes, yes - staff have families, etc...

But hey - so do parents....

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Iamnotinterested

- I'm blushing now - Many thanks, I do sincerely try to help where I can. Just passing it on really - as so many have helped me her on MN along the way!

I second Iamnotminterested. Thank you so much PastSellByDate!

I always find your posts very useful, and I like all the ideas for games to have fun while practising numbers.

The snap game to practice number bonds using a normal deck of cards is brilliant! My son is going to love it, he is into number games at the moment.