hto

Counters can be exchanged down one at a time. A single counter from the tens column bursts into 10 ones when it is dragged across.

Counters can be grouped into sets of 10 and exchanged up by dragging into the next column.

Tap the column totals to hide them.

Tap the screen to make counters in different columns. They can be selected and dragged around to arrange them.

hto helps children to learn about place value in a visual way. It is particularly useful for children who are just beginning the process of arranging calculations in columns. The visual way in which the app works helps students to become proficient at pencil and paper addition and subtraction.

Free to download for iPad, iPhone and most Android devices.