Subtract 1-digit numbers with regrouping

The  exercise appears under the Early Math Math Mission. This exercise continues to strengthen understanding of subtraction as taking away groups of ones and tens from each other.

Types of Problems
There are two types of problems in this exercise:


 * 1) Take the tens away This problem has a subtraction problem that involves subtracting two numbers and concentrates on viewing the tens digit. The student is expected to fill in the blanks with the correct answers to arrive at the difference.Sw100l2-2.png
 * 2) Take the ones away: This problem has a subtraction problem that involves subtracting two numbers and concentrates on viewing the units digit. The student is expected to fill in the blanks with the correct answer to arrive at the difference.Sw100l2-1.png

Strategies
Knowledge of subtraction as "take-away" is sufficient to complete this exercise.
 * 1) This exercise helps to understand the concept of subtraction via placeholders.
 * 2) The numbers are larger in this exercise than Level 1, and involve subtraction in each place (tens and units).
 * 3) No borrowing (regrouping) is needed at this stage, so this problem can be done by mentally computing the difference, then filling in the blanks appropriately based on that final answer.

Real-life applications

 * 1) Understanding the place value at this stage will assist with borrowing with subtraction in the more advanced grades.
 * 2) Subtraction is used to represent the idea of taking away in any context, for example, when buying objects in a store.