You can use estimation to find the product of two decimals by rounding both the decimal’s so the nearest tenth or tens place (depending on how long it is) and then multiplying the decimals.
for example, if you had 4.6 and 8.9, you have to round the 4.6 and 8.9. you round the 4.6 up to 5 because the 6 bumps the 4 up to 5) and then round 8.9 to 9 (because the 9 bumps the 8 up to 8.) then, multiply 5 and 9 and you get 45!
Here’s an example , say you were given 8.45 , & 4.55 , first you’d round them both up (since the decimal place is above 5) , meaning 8.45 would go to 8.5 & 4.55 would go to 4.6, so if you’re adding it & you’re trying to find estimated , estimated would be 13.1 , the actual answer would be 13
