<span><span> When you multiply whole numbers by 10, 100, 1000, and so on (powers of ten), you can simply “tag” as many zeros on the product as there are in the factor 10, 100, 1000 etc.There is a similar shortcut for <span>multiplying decimal numbers </span>by numbers such as 10, 100, and 1000:
Move the decimal point to the right as many places as there are zeros in the factor.</span><span><span><span>10 × 0.49 = 04.9 = 4.9</span><span> </span></span>Move the decimal point one step to the right (10 has one zero).</span><span><span><span>100 × 2.6<span><span>5 </span> </span>= 265. = 265</span><span> </span></span>Move the decimal point two steps to the right (100 has two zeros). The number 265. is 265 (as shown above).</span><span><span><span>1000 × 0.370 = 370. = 370</span><span> </span></span>1000 means we move the point three steps. Write a zero at the end of 0.37 so that the decimal point can “jump over to” that place.</span></span>
for A multiply 85 and 30. then subtract 30 by the product, this gives you the sale price. For B you do the same thing but you multiply 18 and 85. then 18 subtracted by the product which gives you the sale price.
