without multiplying, how do you know that the product of 399 and 48 is smaller than 20,722?
what is 50x400?
20,000
Since 399 is less than 400 and 48 is less than 50, then obviously the answer must be less than 20,000. Right?
the world in the 1400s
how can you show without multiplying that 4/9 is greater then 0.4
To determine if the product of 399 and 48 is smaller than 20,722 without multiplying, we can use estimation or divisibility rules.
Estimation Method:
Step 1: Round the numbers to the nearest 10s or 100s.
Round 399 to 400.
Round 48 to 50.
Step 2: Multiply the rounded numbers.
400 * 50 = 20,000.
Since 20,000 is smaller than 20,722, we can conclude that the product of 399 and 48 is smaller than 20,722.
Divisibility Rule Method:
Step 1: Find the prime factors of both numbers.
399 = 3 * 3 * 3 * 3 * 3 * 3
48 = 2 * 2 * 2 * 2 * 3
Step 2: Determine if the product of the common prime factors is smaller than or equal to 20,722. Since both numbers have a common factor of 3, we can compare the product of the prime factors 3 * 3 * 3 * 3 from 399 and 3 from 48.
3 * 3 * 3 * 3 * 3 * 3 * 3 * 3 = 729, which is smaller than 20,722.
Therefore, the product of 399 and 48 is smaller than 20,722.