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DD not getting what comes after 299 (300) or 399 (400) etc

(20 Posts)
MinimalistMommi Mon 24-Nov-14 12:49:52

But she knows that 100 comes after 99. How can I explain it so she understands? She gets stuck and says 1000 because she wants to give an answer!

atticusclaw Mon 24-Nov-14 12:51:07

How old is she?

MinimalistMommi Mon 24-Nov-14 12:53:41

She is 6 years and 8 months old. We have started the Power Of Two book from Amazon and a question came up Add 1 to various numbers and I realised she could do it to all numbers apart from the ones where it rolled on from 299 add one to make 300.

FelixTitling Mon 24-Nov-14 12:54:09

Depends how old she is, but ds does this sometimes and he is in y4 and is in an extension maths group, so clearly doing ok.

MinimalistMommi Mon 24-Nov-14 12:57:54

Maybe I'm expecting too much. Just gone back to the book. It was adding one. Say out loud the number which is one more than these numbers. Another example was 599. She couldn't grasp that by adding one 599 would be 600.

TheHobbit Mon 24-Nov-14 13:03:16

Maybe say what does 5 plus 1 equals.
She will say 6 then with that

TheHobbit Mon 24-Nov-14 13:03:38

Sorry pressed to quickly. Meant then work with that.

FelixTitling Mon 24-Nov-14 13:04:37

have a word with her teacher maybe. ds plays monopoly like a loan shark, but yesterday couldn't asked me what 4+4 was hmm

LittleMissGreen Mon 24-Nov-14 13:05:00

Can you show her visually e.g. with money - have 5 £1coins, then 99p in tens and pennies. Add one more penny and recount. Swap the now £1 in for a £1 coin. You now have £6 or 600pence.

MinimalistMommi Mon 24-Nov-14 13:06:15

TheHobbit she has no problem adding one to number like 5 or 6 or 15 or what have you. It's just 199>200 or 299>300 or 399>400 etc etc

MinimalistMommi Mon 24-Nov-14 13:07:36

Little I think she does need it visual. This is where I wish I had a 1000 board, she uses her 100 board a lot LOL and finds it useful.

spanieleyes Mon 24-Nov-14 13:12:20

Get a dry-wipe 100 square and show her how you can turn all the numbers into say 200's ( so 201,202, etc up to 299.) Can she now see that the next number must be 300? Then repeat by turning all the numbers into 300's and then the 400's until she gets it!

junkfoodaddict Mon 24-Nov-14 16:53:28

Visual 100 square and as someone said write the hundreds digit in front of each number (1, 2, 3, etc would become 101, 102, 103). I have done this with Year two children before. Also, lots and lots of counting from any number (e.g 189, 294, 396) crossing the hundreds boundary. It's the old saying "practise makes perfect". I wouldn't worry just yet as it is only the autumn term in Y2.

taeglas Mon 24-Nov-14 18:37:16

If you go on sen teacher you can create your own 100 squares starting on any number so you can make 1-100, 101-200,201-300 etc and put them under each other so she can see how the number continues.

Ferguson Mon 24-Nov-14 22:25:29

This isn't exactly what you need, but some of it may help a bit. And, yes, a Hundred Square would probably be useful:

Ferguson Mon 24-Nov-14 22:27:04


Practical things are best for grasping number concepts - bricks, Lego, beads, counters, money, shapes, weights, measuring, cooking.

Do adding, taking away, multiplication (repeated addition), division (sharing), using REAL OBJECTS as just 'numbers' can be too abstract for some children.

Number Bonds of Ten forms the basis of much maths work, so try to learn them. Using Lego or something similar, use a LOT of bricks (of just TWO colours, if you have enough) lay them out so the pattern can be seen of one colour INCREASING while the other colour DECREASES. Lay them down, or build up like steps.


ten of one colour none of other
nine of one colour one of other
eight of one colour two of other
seven of one colour three of other

etc, etc

then of course, the sides are equal at 5 and 5; after which the colours 'swap over' as to increasing/decreasing.

To learn TABLES, do them in groups that have a relationship, thus:

x2, x4, x8

x3, x6, x12

5 and 10 are easy

7 and 9 are rather harder.

Starting with TWO times TABLE, I always say: "Imagine the class is lining up in pairs; each child will have a partner, if there is an EVEN number in the class. If one child is left without a partner, then the number is ODD, because an odd one is left out."

Use Lego bricks again, lay them out in a column of 2 wide to learn 2x table. Go half way down the column, and move half the bricks up, so that now the column is 4 bricks wide. That gives the start of 4x table.

Then do similar things with 3x and 6x.

With 5x, try and count in 'fives', and notice the relationship with 'ten' - they will alternate, ending in 5 then 10.

It is important to try and UNDERSTAND the relationships between numbers, and not just learn them 'by rote'.

I am sorry it seems complicated trying to explain these concepts, but using Lego or counters should make understanding easier.

An inexpensive solar powered calculator (no battery to run out!) can help learn tables by 'repeated addition'. So: enter 2+2 and press = to give 4. KEEP PRESSING = and it should add on 2 each time, giving 2 times table.

There are good web sites, which can be fun to use :


(Sorry - didn't post it properly first time!)

dancingwitch Mon 24-Nov-14 22:34:50

I can empathise with this as 5yo DD get stuck at 29/30, 39/40 etc. I'm trying to explain it to her in terms of all of the units getting full up so the tens is rolling up one.
Presumably your DC can understand how 39 becomes 40 so can you use that as the analogy for 399 becoming 400? If she gets that 99 becomes 100 - which you say she does - then she has got that bit so it is just a question of what number comes first in the hundreds column.
It can be really frustrating when they can't grasp something which seems so simple!

momwhereismy Mon 24-Nov-14 22:35:12

I tell my son that 9 is the last number so in the following number, the first number changes. So I.e what comes after 5...6 so the new number is 600. I hope this comes across as making sense haha

Saracen Tue 25-Nov-14 00:00:28

If she had £2.99 and you gave her another penny, would she know how much money she had?

Try to attach the concept to something concrete which she does understand.

If she doesn't yet have the experience to be able to add a penny to £2.99, give her more time. And more money grin. It will come. I think it is a big mistake to pursue abstractions with children who don't yet have the life experience to have a feel for what the abstractions represent.

MinimalistMommi Tue 25-Nov-14 08:02:12

My little girl has got in this morning!!! Thank you everyone!!!
She doesn't have an understanding of money yet but we do have a dry wipe 100 square board which she uses a lot.

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