23
20 times with a remainder of 23
13 times with a remainder of 20
If the given dimensions are in feet then 23 times 20 = 460 square feet
460 (shortcut : 23 x 2 and add the zero back)
(23 x 2) ÷ (4 x 5) =46 ÷ 20 =2.3
4 with 3 remaining 23 - 3 = 20 = 5 x 4
141+20=161, 161/7=23. The answer is 23. It is algebra
4 with remainder 20.
134 with remainder 20.
Exactly 23 times
You could use 23 * 17 = 23*(20 - 3) = 23*20 + 23*(- 3) = (20 + 3)*20 + (20+3)*(-3) = 20*20 + 3*20 + 20*(-3) + 3*(-3) = 400 + 60 - 60 - 9 = 391. I would however not that the two numbers are 20+1 and 20-3 and so look at the questions as a difference of two squares (DOTS). The answer, then is 23*17 = 202 - 32 = 400 - 9 = 391 So much shorter and simpler.