150 x 20 = 3000
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.
The product of 21 multiplied by 57 is 1,197.
The product of 52 and 21 is 1092
630
The product is 651
The product is: 18,669
The product is 7560
735
21 x 20 = 420
It is simply: 3 times 7 = 21
7 and 4/21 = 151/21
To get to an improper fraction from a mixed fraction, multiply the whole number to the left of the faction by the denominator of the fraction. 7 x 21 = 147. Next, add the numerator of the fraction to the product you just calculated. 4 + 147 = 151. Put the sum you just calculated over the original denominator (151/21).