A good understanding of the base 10 number system is required in order to allow your child to successfully work with decimal numbers.
When teaching decimal numbers, first review the basics of thousands, hundreds, tens and ones and then introduce (or review) tenths, hundredths and thousandths.
Be careful when discussing tenths, hundredths, and thousandths with your children. Pronounce these terms with special emphasis on the “-ths” to help avoid their confusion with tens, hundreds, and thousands.
Tips when teaching decimals
- work with money – explain how the coins related to ones, tenths and hundredths. Note: Emphasize that the decimal part refers to a fraction of a whole dollar as opposed to a whole number of nickels, dimes, or quarters.
- show that the decimal point always separates the ones and the tenths
- ensure your child can read decimals. e.g. 32.46 – say “thirty-two and forty-six hundredths.”
- explain and illustrate equivalent decimals. e.g. 0.4 = 0.40
- show how placing zeros before the leftmost digit does not change the number’s value.
i.e. 007 = 7
- show strategies for comparing decimals. e.g. line up decimal points when stacking numbers.
Start from the left. i.e. if the tenths are bigger then there is no need to compare the hundredths.
These tips, together with the resources on this site will help you when teaching decimals to your child.