Related Calculations Flashcards

All 4 cards in this deck

What are the steps to use a given calculation to answer a related one?

e.g. given $34 \times 26 = 884$, find $3.4 \times 2.6$

1. Check the digits are the same: $34$ and $26$ ✓
2. Count the decimal places in the new question: $1 + 1 = 2$
3. Put the point in the same digits: $8.84$

Given that $1081 \div 23 = 47$, what is $108.1 \div 23$?

$4.7$ — the number being divided is 10 times smaller, so the answer is too.

Given that $23 \times 47 = 1081$, what is $230 \times 47$?

$10\,810$ — one factor is 10 times bigger, so the answer is 10 times bigger.

Given that $23 \times 47 = 1081$, is it true that $2.3 \times 47 = 10.81$?

False. Only one number was divided by 10, so the answer is $108.1$.