Learn two simple Math tricks that will help you multiply 11 faster than a calculator.
Let's first multiply 11 by a two digit number.
11 x 45
1. Split the number 4 5
2. Add the two numbers 4 + 5 = 9
3. The 9 goes between the two split numbers 495
4. 11 x 45 = 495
11 x 21
1. Split the number 1 2
2. Add the two numbers1 + 2 = 3
3. Place the total of adding between the two numbers 132
4. 11 x 21 = 132
11 x 99
1. Split 9 9
2. Add 9 + 9 = 18
3. This time we need to carry ten to the first number 9 + 10 = 19 then place the 8 and the other split number.
4 11 x 99 = 1089
Now let's look at larger numbers.
5434 x 11
1. The first number will be 5 and the last digit will be 4 5 4
2. 5434 add the last digit and the number to it's left. 4 + 3 = 7
3. so now you have 5 75
4. Add 3 and the number to the left 3 + 4 = 7 now you have 5 775
5. Add 4 and the number to it's left 4 + 5 = 9
6. So now you have 59,775 which is the answer.
The video works several more examples if you are confused.
0 comments:
Post a Comment