Transcript Everyday Mathematics Partial-Sums Addition Partial-Sums Addition Partial-sums addition involves: • Understanding place value; • Finding partial sums; and • Adding partial sums to get the final.

Everyday
Mathematics
Partial-Sums Addition
Partial-Sums Addition
Partial-sums addition involves:
• Understanding place value;
• Finding partial sums; and
• Adding partial sums to get the final answer.
Everyday Mathematic
Partial-Sums Addition
Solve: 634 + 918
We begin by thinking of the expanded notation for the
numbers being added.
634 = 600 + 30 + 4
918 = 900 + 10 + 8
With partial-sums addition, we can start from the right or
the left. Children often prefer to start from the greatest
place-value position.
Everyday Mathematic
Partial-Sums Addition
First we add the hundreds.
634
+ 918
600 + 900 = 1,500
The numbers written in blue show our thinking and the
numbers written in black show what we write to solve
the problem.
Everyday
Partial-Sums Addition
Next we add the tens.
634
+ 918
600 + 900 = 1,500
30 + 10 =
40
Everyday
Partial-Sums Addition
Then we add the ones.
634
+ 918
600 + 900 = 1,500
30 + 10 =
40
4+8=
12
Everyday
Partial-Sums Addition
Finally, we add the partial sums to find
the answer.
634 + 918 = 1,552
634
+ 918
1,500
40
+ 12
1,552
Everyday
Partial-Sums Addition
When children use partial-sums addition, they practice skills
related to number sense and algebraic reasoning. For example:
• Understanding and using place value;
• Thinking about numbers in expanded notation; and
• Using addition fact extensions such as 600 + 900 = 1,500.
If children work from left to right, which is generally their
inclination, they begin the problem-solving process with a
reasonable estimate of what the final answer should be.
Everyday Mathematic