The Standard Algorithm for addition is shown below along with two step-by-step lessons that you can work through with your children to practice using it. Note that, before using the algorithmic method as illustrated below, your children should be familiar with the place value strategies that are the basis of the algorithm.
Work with your child to help him or her understand the concept of regrouping when adding numbers. The illustrated example below can be used to help explain this. Also, activities with money, such as adding cents and then exchanging groups of ten for dimes will also help master the concept of regrouping.
We use the base ten number system to write numbers with each place having a value; ones, tens, hundreds, thousands, and so on.
When we add numbers we often have to combine these groups if we end up with more than 9 in any one group. Below is an example of addition with regrouping.
|Start by adding the ones. We have 12 ones but only one place!||We must regroup our 12 ones to give 1 ten and 2 ones||Now we can put the 1 ten with the tens and write 2 in the ones place||Finish by adding the tens including
the 1 ten that was regrouped
2 + 3 + 1 = 6
Watch an animated example showing each of the steps from the above addition.
Follow the instructions below to enter your own numbers to add and watch the steps required to complete the calculation.
Read the lesson below and then work through it with your children. Print off any required worksheets and gather whatever materials are required before starting.
Students normally learn best when they can associate what they are learning with what they already know. This introduction will provide your child with an opportunity to do this and help prepare him for the new content to be learned later in this lesson. This introduction (or warm-up) typically takes 10-15 minutes. Do not worry if it takes longer.
Materials Needed: About 50 buttons, or coins (ideally some sort of item that students can count with)
This part should take around 20 to 30 minutes but you can take as long as necessary.
Tell your children that you will show them how to solve addition problems by exchanging 10 ones for 1 ten.
Tell your children that you will now show them how to solve subtraction problems by exchanging 1 ten for 10 ones.. Explain that when students are subtracting in a problem and do not have enough in a digit to take or subtract from, they must exchange 1 ten for 10 ones.
Note: Remind your child that not all 2-digit addition and subtraction problems require carrying over or borrowing. e.g. 23 + 44 or 87 - 26. Set up a variety of addition and subtraction questions using this worksheet generator.
The 3 worksheets and worksheet generator listed above are grouped below:
And for a final challenge, you can help (if needed) your children with this 4-Page Addition/ Subtraction worksheet that promotes and demonstrates a full understanding of the addition and subtraction algorithmic methods - it gets progressively more challenging.