Ian multiplied a whole number by 5. He then multiplied that product by 2. What digit is in the ones place of the final product?
The product of any number multiplied by 5 is either 5 or 0. (5, 10, 15, 20, 25, 30, etc.)
If you multiply any of these products by 2, what do you think will be the last digit?
answer is "0"
50
To find the digit in the ones place of the final product, you need to follow these steps:
1. Start with a whole number.
2. Multiply the whole number by 5.
3. Multiply the product from step 2 by 2.
4. Identify the digit in the ones place of the final product.
Let's go through the steps using a specific example.
Let's say the whole number is 7.
Step 1: Whole number = 7
Step 2: 7 multiplied by 5 equals 35
Step 3: 35 multiplied by 2 equals 70
So, when multiplying a whole number by 5 and then by 2, the final product is 70.
The digit in the ones place of the final product is 0.