Bridge-to-ten strategy
For example, the picture above portrays the equation 5 + 4 = 9. As the added number which is 4 is a positive value, so the arrow will move four steps to the right side of 5.
This model is also applicable for subtraction where the arrow will move to the back to indicate the decreasing value. For example: 5 – 4 = 1. The arrow will move four steps to the left of 5 (National Council of Teachers of Mathematics, 2011).
Partitioning
Breaking the equation into bridge to ten strategy:
8 + 7 = 15
8 + (2 + 5) = 15
