Where on the Number Line? Twenty to Forty

Twenty is the first number printed on every line of this 1st grade number-lines page. Four lines fill the sheet, one to a cream card, each running from 20 to 40 with labels at 20, 25, 30, 35 and 40 and a tick for every whole number in between. Three orange arrows stand on each line pointing down at ticks that carry no number of their own, and above every arrow floats an empty dashed box. Twelve numbers to write in all, and none of them is a multiple of five, because the labelled ticks are the ones already answered.

A number line that begins at zero lets a child count from the left end and still be right. This one closes that door: the count has to start from a printed landmark somewhere in the middle of the twenties or thirties, which is the whole reason for the range. Naming the tick after 33 means holding thirty-three, stepping one, and saying thirty-four, and the thirties are the decade where children most often lose the pattern and produce twenty-ten or forty-one. Watching which direction the counting goes is worth the effort too, since counting back from 35 to reach 34 is quicker than counting on from 30 and is the habit that leads to estimation.

Print the PDF free and ask for the label counted from to be pencilled in beside the first box on each line, so the route taken is visible on the paper. Missing numbers on a number line runs the identical layout from 0 to 20 if the twenties are still new, and number line 40 to 60 and number line 60 to 100 carry the same idea further up for second grade.