Estimating the product of 68 and 21 . . .
It is easy in your head to think that this product would be close to 70 times 20. Again, in your head, you can figure that product to be 1400.
89 - 21 = 68
2 x 2 x 17 = 68
90 x 70 = 6300
21 as a product of its prime factors is 1 X 3 X 7.
To round to estimate the product of 38 x 2, you first round each number to a more manageable value. In this case, you can round 38 to 40 and 2 to 0. Then, multiply the rounded numbers together to get an estimate of the product. In this case, 40 x 0 = 0. So, the estimated product of 38 x 2 is 0.
1428
68
68-21 = 47
68 multiplied by 21 is 1,428
150 x 20 = 3000
The product is 68
$68
21 can go into 68 three times, as 21 multiplied by 3 equals 63, which is the largest multiple of 21 that is less than or equal to 68. The next multiple, 21 times 4, equals 84, which exceeds 68. Therefore, 21 fits into 68 a total of 3 times with a remainder of 5.
68 x 52 = 3,536
34 multiplied by 68 is 2,312.
To find 21 percent of a number, multiply the number by 0.21. In this instance, 0.21 x 68 = 14.28. Therefore, 21 percent of 68 is equal to 14.28.
68 x 16 = 1088