The number line
Counting gives numbers in order. What changes when each number gets its own place on a line?
Where you are 2 inside
What this area is about
A number line turns the counting list into a picture. Each number gets a spot, the spots are evenly spaced, and the numbers grow to the right. Once numbers are laid out like that, a child can see which of two numbers is bigger, how far apart they are, and what lies between them.
How these fit together
Placing numbers. Placing a number on a number line puts whole numbers on a line where each mark is one more than the last, and reads which number comes later.
Changing the scale. Number lines with different scales reads lines whose marks step by 2, 5, 10 or 100, so a line from 0 to 1{,}000 still fits on a page.
A path through it
Place numbers on a line marked in ones first, then read lines with bigger steps.
The number line comes back again and again: adding on an open number line, decimals on a number line, integers, and later the axes of every graph.