Once children have shown that they can count up to 20 or so it is often presumed that they are then OK counting up and down with larger numbers. This may well not be the case and children do need plenty of practice counting on and back, especially when this involves crossing the tens boundary. For example, to be able to count down in ones from 52 a good knowledge of counting up in tens is needed, so that the transition from 50 to 49 is completed successfully. This page gives practice at counting down in ones, crossing the tens boundary and is one of a number of similar sets of worksheets. Go to our Counting back crossing the tens boundary worksheets