Skill 7D
Regrouping Across One Zero: 3 Digit Numbers

Subtracting from a "0" is a confusing concept since it appears that there is nothing that can be  "regrouped" (borrowed).   Therefore, if your student has trouble with this skill be sure to download the practice worksheet and teach these steps:
1) Since we cannot regroup (borrow) from the zero, we must jump over to the next column (hundreds).
2) We then take one from the hundreds place and put it in front of the zero in the tens column (or just cross out the zero and  write a "10" over the "0." 
3) Now we go back and subtract normally - Sine the 9 is bigger than the 5 in the ones column we borrow (regroup) from the "10" that we put over the zero.  The 5 in the ones column becomes a 15 and the 10 in the tens column becomes a 9. 

Write this subtraction problem on a separate paper and solve.
What is the correct answer?

 

405
- 399