As an expert in the field of mathematics education, I have a deep understanding of various mental math strategies that can be employed to simplify the process of addition, especially for younger students or those who are still developing their arithmetic skills. One such strategy is the "Doubles Plus One" method, which is a part of the broader collection of mental math strategies aimed at making addition more accessible and intuitive.

The "Doubles Plus One" strategy is particularly useful for solving addition problems that involve numbers which are close to each other, such as 5+6 or 7+8. The concept is straightforward: it involves starting with a number (let's call it the base number), finding its double, and then adding one more to that doubled amount. This method leverages the fact that many children can easily recognize and calculate doubles of numbers, which makes it an effective way to tackle addition problems that might otherwise be more challenging.

Let's delve into the strategy with a step-by-step explanation using a few examples:


1. Identify the Base Number: Choose the smaller number in the addition problem as the base number. For instance, in the problem 5+6, the base number is 5.


2. Find the Double: Multiply the base number by 2. Continuing with our example, the double of 5 is 10.


3. Add One: Since we are adding a number that is one more than the base number, we simply add 1 to the doubled amount. So, 10 (the double of 5) plus 1 equals 11.


4. Check Your Work: It's always a good practice to verify your answer. You can do this by subtracting the base number from your result and checking if you get the other number in the addition problem. In our example, if you subtract 5 from 11, you get 6, which confirms our answer is correct.

This strategy can be applied to a wide range of addition problems. Let's look at another example:

- Problem: 7+8
- Base Number: 7
- Double: 7 * 2 = 14
- Add One: 14 + 1 = 15

Again, you can check your work by subtracting the base number (7) from the result (15), which should give you the other number in the problem (8).

The beauty of the "Doubles Plus One" strategy is that it not only helps students solve addition problems more quickly but also reinforces their understanding of number relationships and the concept of doubling. It's a method that can be taught early on and used as a stepping stone to more complex arithmetic operations.

Moreover, this strategy can be adapted to subtraction problems as well. For example, if you were to subtract a number that is one less than the base number, you would start with the double of the base number and then subtract one.

In conclusion, the "Doubles Plus One" strategy is a valuable tool in the mental math arsenal. It's a simple yet effective technique that can greatly enhance a student's ability to perform addition and subtraction quickly and accurately. By mastering this method, students can build a strong foundation in arithmetic that will serve them well in more advanced mathematical studies.

read more >>

Doubles Plus One: a Mental Math Strategy Unit. This unit is part of the addition portion of the Mental Math Strategy Collection. Doubles Plus One equations include facts such as 5+6 and 7+8. Using the doubles plus one strategy, a student begins with a known double and adds one more.read more >>