We did two hands-on activities to gain a better understanding of place value.
While beginning the study of decimals, my son was asked to do some rounding. This proved very difficult for him mainly because he had difficulty understanding the meaning of place value on the right-hand side of the decimal point. So we took a step back from rounding and worked on place-value instead.
First I cut 1 cm x 1 cm units from a sheet of paper. I gave them to my son and asked him to write down how many there were. - No problem -
So I took a fresh 1 cm x 1 cm unit, drew 10 lines and cut of a tenth and asked him to write down how much that one was. He was baffled.
So we got out some money. Money is a great starting point for the decimal system because pennies, dimes, dollars and ten dollar bills are pure examples of the place values.
He was given 1 dollar, 1 dime and 1 penny and asked to write the value. Here's what he wrote.