I am learning to solve two digit subtraction problems by subtracting in parts eg,
46 - 23=, 46 - 20 =26, 26 - 3= 23
(Stage 5 -Hero)
S5 Solve 2 digit subtraction problems by subtracting in parts.mp4
St5 LI5 #1.pdf
This 'prove it' shows that this strategy can be achieved, but to show application of this knowledge the word problems in the post test should be completed.