At the time, I assumed that estimating distance was less a learnable skill and more a gut feeling. Hence my surprise when I recently came across a quick eyeball-and-mental-math trick that allows ...

The number line to 10,000 Learn how to estimate and label numbers up to 10,000 on a number line. Number line to 100 and 1000 Learn how to write and work out numbers on a number line to 1000.