Addition and Subtraction
 Have children find the total number of pages in one mathematics and in one science textbook. Encourage some children to model the problem using placevalue charts and blocks. Emphasize regrouping as it is needed.
 Once children have grasped the concept of regrouping, introduce money amounts greater than 99 cents, using decimal notation.
 Have children orally explain how adding and subtracting money is similar to adding and subtracting 3digit numbers.
 Encourage the use of grid paper to properly align digits in addition and subtraction problems. It is a useful aid for those children having difficulty keeping digits in proper columns.
 If children are experiencing errors in addition or subtraction, have them write the problems in placevalue charts. Writing the digits in the chart will help align columns for easier computation.
 Urge children to check their answers by using the inverse operation. This not only reinforces use of another operation, but also provides additional practice in number facts.
 If children are forgetting to add the regrouped digit to the next column, have them write the digit lightly above the correct place. It may be necessary to circle this digit so that it is not forgotten.
 Set up a grocery store in the classroom by using empty boxes of foodstuffs. Write a price on each box, and allow children to "shop." Have children take turns being the clerk who finds the total of the purchases.
 
Addition and Subtraction
with Regrouping:
Commutative and Associative Properties:
