​Comparing

• Problems about comparing often ask questions like "how much less?" or "how much greater?"

​Example: During the day 1320 employees work at the factory. At night 897 employees work there. How many more employees work in the factory during the day than at night?

• When we subtract, we find that 423 employees work during the day than at night!

​Elapsed Time

​Elapsed time: the length of time between two points in time.

​Example: Dr. Martin Luther King, Jr. was 34 years old in 1963 when he delivered his "I Have a Dream" speech. In what year was he born?

• We subtract 1963 from his current age (34 years old):

  1963 - 34 = 1929

• Dr. Martin Luther King, Jr. was born in 1929.

​Daily Challenge #12
John F. Kennedy was elected president in 1960 at the age of 43. In what year was he born?

​Still confused about the lesson?