Here are two examples
Divide the two-digit number by the one-digit number. If the remainder is zero then the 2-digit number is a multiple and if not, it is not.
A one digit number is a number with only one number. For example: 12 is a two digit number. It has two numbers. 3 is a one digit number because it only has one number.
13
9 and 99
Multiply the three-digit number by the one's digit, or last digit, of the two-digit number. That is your first part. Now multiply by the second-to-last digit, or ten's digit, and multiply the result by 10. That is your second part. Add the two parts and that is your answer.
Here are two examples
Divide the two-digit number by the one-digit number. If the remainder is zero then the 2-digit number is a multiple and if not, it is not.
A one digit number is a number with only one number. For example: 12 is a two digit number. It has two numbers. 3 is a one digit number because it only has one number.
17 \
13
-99
2.3
To multiply two digit numbers, multiply each place value of a factor by each place value digit and add the results.
To calculate 12 x 90, you simply multiply the two numbers together. 12 x 90 = 1080. This is because when you multiply a two-digit number by a two-digit number, you multiply the ones place of the first number by the ones place of the second number, and then the tens place of the first number by the ones place of the second number, and so on.
It is 97.
Divide the 2-digit number by the 1-digit number. If the quotient comes out a whole number, then the big one is a multiple of the small one.