Two-Digit Addition With Regrouping: Tips and Tricks

• Begin the chapter by having children practice skip counting by tens. Use a number line or hundred chart.
• Provide a variety of materials, such as paper clips, beans, craft sticks, and so on, for children to use when regrouping.
• Provide as many experiences as possible for regrouping during the school day. For example, when children line up, ask them how they can find out how many are in line. Work through the situation to find the answer.
• If children fail to add the regrouped ten to the sum, have them circle the ten with a colored pencil.
• In the Math Center, have laminated tens and ones mats for algorithms and wipe-off markers available. Or have children use Workmat 3 in the back of their text. Children can make up their own problems and have a friend solve them.
• Make sure children do not try to regroup when there are fewer than 10 ones. Remind them that they will not regroup every time they add.
• To help children understanding the regrouping of tens and ones, have them choose a number between 11 and 50 and model that number in different ways.
• To reinforce regrouping, place number cubes or spinners and tens and ones blocks in the Math Center. Have children take turns rolling the number cube or spinning the spinner, taking that number of ones. As soon as they accumulate 10 ones, they exchange them for a ten. Children play until they make 5 tens.
• If children have trouble adding money, give them ten-frames and pennies and dimes to model the process. Have them regroup the pennies on the ten-frames first, trade for a dime, and then add the dimes.
• Set up a classroom store in which items are labeled with two-digit prices. Have children take turns buying two items and finding how much they owe.
• If children can't keep their numbers in alignment, draw a vertical line between the tens column and the ones column or highlight the ones column in yellow.
• When introducing the rounding of numbers to estimate a sum, hang a number line in the classroom. Highlight all the numbers with five or more ones. Explain to children that 5 and the numbers to the right of 5 should be rounded to the nearest ten on the right side, while the numbers to the left of 5 should be rounded to the nearest ten on the left side.