dd struggling with decimals and negative numbers, anyone got any tips or links to info that might help?

[nipersvest]

just been doing dd's half term maths homework and it's quite clear she has not got her head round decimals and negative numbers, i'm tying myself in mental knots attempting to explain.

anyone got any advice?

she's 11, year 6, top set in maths, although i'd say she's in the bottom group of the top set. quite capable at most maths usually but has always had a bit of a blind spot with decimals etc.

BBC is quite good. Here

Real world physical examples,
Decimals, ruler, stacks of ten Lego bricks, adult graph paper clearly marked in groups of ten squares, money.

Negative numbers, I managed to explain to DD2 when she was about 6 using the same idea as the key on an atlas.

We drew a man on a cliff +ve numbers gong up the cliff,
Negative numbers diving deeper in to the sea.

Some activities with decimals here

Mine cracked negative numbers through using a thermometer.

Negative numbers as a debt? You have £3 in your purse but owe dd £5 pocket money, so th overall effect is that you have -£2. You also owe her cousin £5 so your total debt is £7, so -£2 + -£5 = -£7

decimals- money/measurement is a good way
so 567cm+345cm = 5.67m+3.45m

negative numbers, it really depends on what she has been asked to do,

I was taught -ve numbers by drawing a ladder with numbered rungs (0 in the middle), and you climbed up and down the ladder.

Going to sound like a boast, but my 5yo ds got very interested in temperature (whether it would snow) last winter, and worked out negative numbers, adding and subtracting them etc. Can you use a thermometer to show her? Sometimes having something "real" to see can help.

For decimals, I would do a lot of place value work, making sure that is secure before moving on.

thanks for those links/tips, they will certainly help

When DS1 (Y8) is struggling with a concept in Maths, he suddenly seems to understand when I use his money to demonstrate.

For decimals you could bake a cake or pizza. Obviously explain this is 1 whole cake but can be cut into smaller parts e.g. tenths. Show her how to write this as a fraction and as a decimal. Get cutting and eating. How many tenths are left? Is this more or less than 1 whole etc.

For negative numbers I would go for real world examples. Temperature would be good at the moment. Draw her a big thermometer and talk about the weather temps you can find on bbc weather website. Debt would also be a good one as quite topical at the moment!

Lots of children struggle with these things. Keep it as visual as possible. Lots of drawings. I think you can buy fraction and decimal posters too which you could put in her room.

I saw a TV program once where they were doing negative numbers outside relating it to digging down into the ground. So level ground would be zero. One dig down negative 1 etc. and then adding earth back into the negative 1 hole (i.e. adding 1) would be zero. I've used it since with DS and seems to work

number line for negatives is helpful so I love suflowers ideas are brilliant. also down into the basement or up the stairs to the first floor.

Casey runner is very good for addition and subtraction of negative numbers.

Sorry, forgot to add, it is a game. If you Google you should find it.
There are also probably good things on the woodlands junior school website.

Hi nipersvest:

Agree with Loughrigg Woodlands Junior School Mathszone is often a great place to start. link here for decimals: resources.woodlands-junior.kent.sch.uk/maths/fractions/index.htm#Percentages

Unfortunately I couldn't find anything for negative numbers, but DeWe is right, often explaining this with temperature is a great way to help add or subtract negative numbers.

BBC bitesize has a negative number game here: www.bbc.co.uk/bitesize/ks2/maths/number/negative_numbers/play/ and a recap about decimals here: www.bbc.co.uk/bitesize/ks2/maths/number/decimals/read/1/

Primary resources has various worksheets (by year) for negative numbers here: www.primaryresources.co.uk/maths/mathsB1b.htm and for decimals here: www.primaryresources.co.uk/maths/mathsB6b.htm

Because your DD is Y6 she may respond better to a more 'grown-up' form of explanation so have a look at this video on negative numbers from the Khan Academy here: www.khanacademy.org/math/arithmetic/absolute-value/add-sub-negatives/v/negative-numbers-introduction and an explanation of decimals/ place value here: www.khanacademy.org/math/arithmetic/decimals/decimal_place_value/v/decimal-place-value.

A really useful thing to do when working with decimals is to get them to think about them as fractions so 0.3 = 3/10 and 0.03 = 3/ 100. This is important because of percentages 3% = 0.03. There's a sweet ordering game (video here: www.bbc.co.uk/learningzone/clips/mr-numbervator-decimal-place/806.html - and this may be a useful thing to work on at home as well. I've also found working with measuring tapes and measuring things is useful (0.34 of a metre long table mat, etc...) and then you can work with adding and subtracting - same rules apply but decimal place has to be all lined up (if vertical addition/ subtraction). Multiplication/ division - respect the decimal places - so do the multiplying/ dividing - but then go back and count how many decimal places are you dealing with - so say in 8 x 0.03 (there are 2 decimal places) - ignore it for the moment 3 x 8 = 24 now return two decimal places 0.24 (which is indeed the answer).

HTH