Find the highest common factor of $$210 and $$400.

Sure, here are the steps to find the highest common factor (HCF) of 210 and 400:

Step 1: Prime factorization of the numbers

• Prime factorization of 210 = 2 * 3 * 5 * 7
• Prime factorization of 400 = 2^4 * 5^2

Step 2: Identify the common factors

• The common factors are 2 and 5.

Step 3: Multiply the lowest power of common factors

• The lowest power of 2 in both numbers is 2^1.
• The lowest power of 5 in both numbers is 5^1.

Step 4: Multiply these common factors

• 2 * 5 = 10

So, the highest common factor (HCF) of 210 and 400 is 10.