How do we multiply quickly decimals by 10 or 100 mentally?
To multiply a decimal by 10, move the decimal point in the multiplicant by one place to the right.
Here we multiplied the number 834.7 by 10 so we move 1 place to the right.
To multiply a decimal by 100, move the decimal point in the multiplicant by two places to the right..
How do you know where to put the decimal when multiplying?
To figure out where the decimal belongs in your answer, put your fingers on each decimal in the numbers you multiplied together. Then, trace the decimals until your fingers meet at a corner in the lattice. Follow the diagonal from that spot to your answer. That is where your decimal belongs in the answer.
Which way do you move the decimal point when multiplying by 10?
If you multiply a decimal by 10, the decimal point will move one place to the right. If you divide a decimal by 10, the decimal point will move one place to the left.
Why do you move the decimal when multiplying?
This explains why we can begin multiplying decimals by multiplying the values like we would whole numbers, without regard to the decimal point. It is because, in the fraction form, the decimal point no longer determines the place value. So Why Can We Just Count up the Decimal Places for the Decimal Point in the Answer?
What is the product when you multiply decimals by 1?
Step 1: Multiply the two numbers as two whole numbers. Thus, 36 × 13 = 468. Step 2: Now, there is one digit each after the decimal point in the factors. So, the product will have 1 + 1 = 2 digits after the decimal point.