Question

do these problems in your head. use paper only for the problems that you just cant do in your hea do as many of these problems without paper as you can. do not use a calculator at all. 38 × 1000 = 1 thousand × 650,000 = 98 × 1 million = 25 × 10,000 = 10,000 × 5 thousand = 4 × 3000 = 3000 × 5000 = 5 million × 2 = 9 × 30 million =

Explanation:

Step1: Multiply by 1000 (add 3 zeros)

$38 \times 1000 = 38000$

Step2: Convert "1 thousand" to 1000, multiply

$1000 \times 650000 = 650000000$

Step3: Convert "1 million" to 1000000, multiply

$98 \times 1000000 = 98000000$

Step4: Multiply by 10,000 (add 4 zeros)

$25 \times 10000 = 250000$

Step5: Convert "5 thousand" to 5000, multiply

$10000 \times 5000 = 50000000$

Step6: Multiply 4×3, add 3 zeros

$4 \times 3000 = 12000$

Step7: Multiply 3×5, add 6 zeros

$3000 \times 5000 = 15000000$

Step8: Convert "5 million" to 5000000, multiply

$5000000 \times 2 = 10000000$

Step9: Convert "30 million" to 30000000, multiply

$9 \times 30000000 = 270000000$

Answer:

$38 \times 1000 = 38000$
$1 \text{ thousand} \times 650,000 = 650000000$
$98 \times 1 \text{ million} = 98000000$
$25 \times 10,000 = 250000$
$10,000 \times 5 \text{ thousand} = 50000000$
$4 \times 3000 = 12000$
$3000 \times 5000 = 15000000$
$5 \text{ million} \times 2 = 10000000$
$9 \times 30 \text{ million} = 270000000$