Mathematics
From Belinda Haley and Cheryl Barker, Mathematics Steering Committee
Understanding the strategies of Ann Baker’s Secret Code
Turn Around (ta)
The turn around strategy simply means to count on from the largest number. When you are
adding 2 and 4, do a turn around, and count on from 4. Students need to know it is more efficient
to add on from the largest number. More importantly, this strategy also teaches the students that
2 + 4 = 4 + 2, which is the start of algebraic reasoning. In mathematics, the commutative law says
you can swap the numbers around and still get the same answer when you add or multiply.
2
+
4
=
4
+
2
turn around
ta
Friendly Numbers (fn)
A friendly number is any number that ends in 0. It is easy to add on to 10 because 10 is a
friendly number. So are 20, 30, 40 and so on.
10 + 6 = 16
40 + 6 = 46
The friendly numbers can also be used to assist with counting on by 10. For example if you had
to add the following, 18 + 26, we can do the following:2
+
10
+
10
+
4
18
10
=
44
44
20
30
40
Landmark Numbers (ln)
The landmark numbers are 25, 50, 75 & 100. They make addition of larger numbers easier.
Students need to know all the combinations such as
25 +25 = 50,
50 + 50 = 100,
25 + 50 = 75,
75 + 25 = 100
This can be extended by using the following landmark numbers:- 250, 500, 750, 1 000 and
further again using 2 500, 5 000, 7 500 and 10 000.
http://naturalmaths.com.au/