Front End Multiplication Technique

Front end Multiplication Technique

The Front End Multiplication Technique is a streamlined and efficient method for performing multiplication operations, particularly useful in mental math Front end Multiplication Technique or when dealing with large numbers. Unlike traditional long multiplication, which starts from the rightmost digit and works toward the left, the Front End Multiplication Technique begins with the leftmost digits, reducing the complexity of the process.

In front end rounding, each of the numbers in a problem is rounded to one digit with the rest of the digits being zero. Standard rounding rules are used. So the second digit in the number is used to decide whether the first digit will be rounded up or down. If the second number is 0, 1, 2, 3, or 4, the first digit stays the same (rounds down). If the second number is 5, 6, 7, 8, or 9, the first digit is rounded up.

For Example:

Front End Multiplication Technique
Front End Multiplication Technique

example Front end Multiplication Technique rounding?

Front end Multiplication Technique Front end rounding is very useful when trying to figure out how much something will cost. If each apple costs $.79, approximately how much will 12 apples cost? Round $.79 to $1.00 and 12 apples to 10 apples.

$1.00 X 10 apples = approximately $10 for 12 apples.

The actual cost is $9.48, so front end rounding was a little high.

Example: Let’s consider the multiplication of 43 and 27 using the Front End Multiplication Technique:

  1. Start by multiplying the leftmost digits of both numbers (4 and 2): 4 × 2 = 8
  2. Append the result to the leftmost side, creating the initial part of the answer: 8…
  3. Next, multiply the leftmost digit of the first number (4) by the remaining digits of the second number (7): 4 × 7 = 28
  4. Append the result to the right of the previously calculated part: 8…28
  5. Now, multiply the leftmost digit of the second number (2) by the remaining digits of the first number (3): 2 × 3 = 6
  6. Append this result to the right of the previous part: 8…286
  7. Finally, multiply the remaining digits of both numbers (3 and 7) and append the result: 3 × 7 = 21 8…28621

The result of 43 × 27 using the Front End Multiplication Technique is 8,286,21.

This method simplifies the multiplication process by focusing on the most significant digits first, reducing the need for extensive calculations and making it easier to perform mental math or work with large numbers efficiently.

Front end multiplication

When multiplying mentally, people generally like to do the bigger or important quantities first. This gives an estimate of the value expected. Such an approach is front end or left to right multiplication. Students using this method multiply the tens before the ones and hundreds before the tens and so on. They then add up these partial products to get the final result. This method is based on the distributive property of multiplication over addition.

Front End Multiplication

  • Used when multiplying 1- and 2-digit numbers by a 2-digit number. 
  • May also be called “chunking” or “breaking apart”.

For Example:

Front End Multiplication Technique
Front End Multiplication Technique

8 × 42 becomes

8 × 40 = 320 and 8 × 2 = 16

Then add 320 + 16 = 336 

How Front-End Rounding is Done

When using front end rounding there are a few easy, but specific steps that must be followed:

  1. Look at each number in the problem. For addition this will be the addends, for division it will be the dividend and divisor, etc.
  2. For each number look at the left-most digit. This is the place that will be a non-zero number in the estimation.
  3. Look at the number directly to the right of that digit.
  4. Use the standard rounding technique to decide whether the left digit will be rounded up or down. This means if the second digit is 0, 1, 2, 3, or 4 the left-hand digit will stay the same (round down). If the second digit is 5, 6, 7, 8, or 9 the left digit is raised one number (rounded up).
  5. Do the computation from the initial problem on the new estimated numbers. This produces an approximate answer to the initial problem.