Assuming your students are familiar with the Two Land, Three Land, and Ten Land blocks and are adept at playing the math game Fair Trades DOWN, the instructional sequence for each land is the same as the one below for exporting (subtracting) in Two Land with blocks. Examples from the Fair Lands™ ebook are given for each step in the sequence.
__ Export in Two Land, no recording (because the answer is given), ,
__ Export in Two Land, record just the answer, ,
__ Export in Two Land, record trading and the answer column by column, ,
The final step, recording trading down column by column, is the standard algorithm for subtraction when exporting in Ten Land. When children can record trading down column by column in any land, then doing so in Ten Land becomes just like what they have become accustomed to doing except for the number 10, and you can announce that henceforth, all subtraction will be in Ten Land (base 10), and in a single day, with only a few examples showing how the algorithm models how the children have been thinking when exporting in different lands, you will be able to teach subtraction effectively, the first time, to every child.
YouTube video: (2:46)
YouTube video: (3:21)
YouTube video: (2:37)
YouTube video: (1:18)
YouTube video: (1:44)
YouTube video: (5:11)
YouTube video: (3:12)
YouTube video: (1:00)
IMPORTANT! Do NOT teach the shortcut of sticking 1s about when “borrowing” as is customary in using the standard subtraction algorithm. Doing so causes difficulty in subtracting fractions. The following illustrates a common error in subtracting fractions that persists into adulthood:
Why do America’s Students Rank So Poorly in Math in International Testing
Most teachers take their jobs seriously and care that their students learn. Why, then, for decades, have America’s students ranked near the bottom in math in international testing? To learn who is to blame, click . You will be glad you did.
Two reasons, in particular, account for the overall poor performance of most American students in math. One is time-honored (thus passionately preserved) math lessons in