To find 4 × 59 using mental math, we can use the distributive property, as well as other techniques. Let's evaluate each of the given expressions to see if they correctly compute 4 × 59:
-
(4×60)−(4×1): This simplifies to 240 - 4 = 236, which is 4 × 59. (Correct)
-
4×(50×9): This simplifies to 4 × 450 = 1800, which is not 4 × 59. (Incorrect)
-
4+(50×9): This simplifies to 4 + 450 = 454, which is not 4 × 59. (Incorrect)
-
(4×50)+(4×9): This simplifies to 200 + 36 = 236, which is 4 × 59. (Correct)
-
4+50+9: This simplifies to 4 + 50 + 9 = 63, which is not 4 × 59. (Incorrect)
Thus, the correct expressions that use mental math to find 4 × 59 are:
- (4×60)−(4×1)
- (4×50)+(4×9)