Math Background

Three-Digit Addition and Subtraction With Regrouping: Tips and Tricks

  • Pair children and have each partner choose a number between 101 and 500. Encourage each pair of children to model a subtraction problem using place-value charts and/or base-ten blocks. Allow some pairs to present their results to the class. Emphasize regrouping as it is needed.
  • Bring in copies of a price list or a menu with prices on it. Have children take turns being the customer and “ordering” two items, and being the cashier and adding the total cost of the order. Have children use play money to determine change by subtracting from whole-dollar amounts given in payment. This helps children work with addition and subtraction of money.
  • Ask pairs to find the total number of pages in each of two textbooks. Then have them work together to estimate the total number of pages in both books. Allow some pairs of children to share their results and methods.
  • Encourage the use of grid paper to properly align digits in addition and subtraction exercises. It is a useful aid for children having difficulty keeping digits in proper columns.
  • If children are experiencing errors in addition or subtraction, have them write the exercises in place-value charts. Writing the digits in the chart will help children align the digits for easier computation and will remind them of the value of each digit.
  • Urge children to check their answers by using the inverse operation. This not only reinforces the use of another operation, but also provides additional reinforcement of basic facts.
  • If children are forgetting to add the regrouped digit, have them write the digit lightly above the correct column. It may be necessary to circle this digit so that it is not forgotten.

Houghton Mifflin Math Grade 2