Help! Multiplying decimals

[basildonbond]

Help please - I'm having an extremely dim moment

ds (y5) has multiplying decimals for homework and is a bit stuck ... as am I !

I'm ok on things like 3.4 x 7, but am wobbly when both sides have decimal points like 6.7 x 4.3 and even worse on 0.345 x 0.34

there is obviously a method which I've forgotten so please can anyone enlighten me?

Ds insists they've not done this at school and the guidance notes are just examples of whole numbers which we're both fine on

thanks

[SayHitIsntSo]

if one number has 2 decimals
and one has 3 decimals
then the result should have 5 decimals (if the last decimal is 0, then ofcourse omit it).

here's a good explanation-
here

HTH

[RupertTheBear]

I would teach it as the grid method (which he should know for multiplying whole number). So you split the number into it's parts (e.g. 3.4 becomes 3 and 0.4) then mulitply each part together. Then add all the answers at the end.
That explanation is probably as clear as mud if you don't know the grid method - let me know if you want me to explain more clearly!

[basildonbond]

thanks say that link is very clear

rupert I have an aversion to the grid method so try to avoid if at all possible, but thanks anyway



phew, I don't have to look completetly dim in front of my children (at least no more than usual ) - literacy, history, languages, anything arts-based or science I'm fine on but maths ..... it's just all melted out of my brain (and I got an A at o-level so I must have understood it once ...)