Strategies For Addition
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1
2Strategies for Addition
place value methods
Second graders are learning to add two digit numbers. When students solve these problems they are focusing on
to add
and subtract. They are not using the standard algorithm to add. By using different strategies, they gain a deeper understanding of place value that
will eventually lead to using the standard algorithm in later grades. The purpose of these strategies is to encourage flexible thinking to compose
some
(put together) the numbers in a variety of ways. Below are
strategies we teach in second grade. As students gain an understanding of
numbers and place value, we encourage them to develop their own strategies to use for addition.
Using a hundreds chart
Break apart strategy
Students will start with the first number. Then break the second
With this method, both numbers get broken into expanded form
number into tens and ones. On the chart, use the columns to
and students add the tens, then the ones. Finally, they combine
add the tens and the rows to add the ones.
those totals for the sum.
23 + 36 = 59
36 +
43
30
6
30
6
40
3
30 + 40 = 70
6 + 3 = 9
79
Then 70 + 9 =
Draw a number line
Draw a model
Students use an un-numbered number line to show their
Students draw a model of the tens and ones blocks we use in the
thinking. In the example below, they start with the largest
classroom. The draw a model of the first addend and the second
number and then break apart the second number. The larger
addend. Then analyze the ones. If there are more than 10, they
jumps represent the tens. (Students can break apart and
will compose those ones into a ten.
combine the numbers in many different ways when using this
strategy.)
51 + 23 = 74
51
61
71
72
73
74
The sum is 4 tens and 2 ones or 42.
Add on tens then ones
Make a friendly number (compensation strategy)
Students break apart one of the numbers. Add the tens and
This is used for numbers that are close to ten. Break apart one
then the ones to the number.
number so that you can make the other number a multiple of
ten (a friendly number). Then add.
32 + 14
56 + 27
10
4
4
23
32 + 10 = 42
56 + 4 = 60
46
42 + 4 =
83
60 + 23 =
Created by Linda James (2013)
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