In this module, you can how learn how to subtract one mixed number from another.
You can change a number into a fraction by putting it 'over' 1.
For example, you can change 3 into 
and you can change -2 into 
Practice and study
0.00 min addition (+), subtraction (-), multiply (x), divide (÷)
1.19 min decimal point
2.43 min C, CE and backspace
4.19 min square, square root & fractions
6.17 min percentage (%)