Subtraction within 1000

The first instance of  is under the 3rd Grade Math Mission. This exercise is the culmination of single digit and two digit subtraction techniques. Students will subtract three digit numbers and use borrowing often.

Types of Problems
There is one type of problem in this exercise:


 * 1) Subtract the numbers: This problem asks the student to find the correct answer when two numbers are subtracted from each other. The numbers used do not exceed 1000, but will often (though not always) use borrowing. Interestingly there are only three problems per set instead of the usual five.Sub10002.png

Strategies
This exercise is easy to get accuracy badges using basic arithmetic. It is easy to get speed badges if one starts to use the calculator to increase speed on problems where it is appropriate.


 * 1) There are only three problems per set, so you will need to go faster to avoid the downtime during loading and calculation.
 * 2) Even if you choose to use a calculator against the spirit of the practice, don't rely on it. Some problems (those without borrowing) are faster to do without a calculator.