5.3 Dates, Times, and U.S./Metric Measurement Problems

5.3 Dates, Times, and U.S./Metric Measurement Problems

Dates and times is one of the item types Wonderlic lists for both the SLE and the SLE-Q. Wonderlic also says test takers must be familiar with U.S. or metric monetary units and the system of weights and measures, depending on which form they take. These items reward careful, orderly comparison more than computation. Many can be answered in a few seconds if you follow a fixed checking order.

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Earliest and Latest Dates

Wonderlic's published sample questions include this format: "Which of the following is the earliest date?" The five choices were Jan. 16, 1898; Feb. 21, 1889; Feb. 2, 1898; Jan. 7, 1898; and Jan. 30, 1889. Compare in a fixed order, from the biggest unit to the smallest:

1. Year first. Two choices are from 1889 and three are from 1898. The 1898 dates are out.
2. Month next. Of the 1889 dates, January comes before February.
3. Day last, only if year and month tie.

The answer is Jan. 30, 1889. The distractors show what these items test:

• Transposed years. 1889 and 1898 use the same digits in a different order. Read all four digits, not just the first two.
• Small day numbers. Jan. 7, 1898 has the smallest day number, which is tempting if you check days before years.
• Month order. Know the month sequence and the common abbreviations: Jan., Feb., Mar., Apr., Aug., Sept., Oct., Nov., Dec.

For latest date questions, use the same order but look for the largest value at each step.

Numeric Date Formats

In the United States, 03/04/2027 usually means March 4, 2027 (month/day/year). Many countries that use metric forms write day/month/year, so the same digits would mean 3 April. If an item uses numeric dates, check which convention it states or implies before comparing.

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Elapsed Time: Count Up in Chunks

To find the time between two clock readings, count up to the next whole hour, then whole hours, then the leftover minutes. This avoids the borrowing errors of column subtraction.

Example: A shift runs from 10:45 a.m. to 3:20 p.m.

• 10:45 → 11:00 = 15 min
• 11:00 → 3:00 = 4 h
• 3:00 → 3:20 = 20 min
• Total: 4 h 35 min

Crossing noon or midnight. 11:00 a.m. to 2:00 p.m. is 3 hours, not 9. Going from a.m. to p.m. crosses noon, so count through 12:00.

Adding a duration. A meeting starts at 9:50 and lasts 1 h 25 min. Add the hour first (10:50), then the minutes: 10:50 + 25 min = 11:15. When the minutes pass 60, carry one hour. For example, 40 min + 35 min = 75 min = 1 h 15 min.

24-hour time. For times after noon, subtract 12 from the hour: 13:45 = 1:45 p.m., and 21:10 = 9:10 p.m. Also 00:30 = 12:30 a.m.

Minutes and Hours as Fractions

Use fractions, not rounded decimals, when you multiply by a rate (see Section 5.1).

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Calendar Arithmetic

• Month lengths. April, June, September, and November have 30 days. February has 28 days, or 29 in a leap year. The other seven months have 31.
• Leap years. A year is a leap year if it is divisible by 4, except that century years must be divisible by 400. So 2000 was a leap year and 1900 was not.
• Day-of-week shifts. Weekdays repeat every 7 days. Divide the number of days that pass by 7 and keep the remainder.
  • If the 3rd of a month is a Tuesday, the 24th is 21 days later. 21 = 3 × 7 with remainder 0, so the 24th is also a Tuesday.
  • The 30th is 27 days later. 27 = 3 × 7 + 6, so move 6 days forward from Tuesday, which gives Monday.
• Same date next year. A 365-day year is 52 weeks plus 1 day. A date usually falls one weekday later the following year, or two if February 29 comes in between.

Age Problems

The difference in ages never changes. Maria is 12 and her brother is three times her age, so he is 36. The gap is 24 years. When Maria is 20, her brother is 20 + 24 = 44. A common mistake is to keep the "three times" ratio: 3 × 20 = 60 is wrong.

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U.S. Customary and Metric Units

Memorize the conversions the test assumes you know:

Conversion rule. Going from a bigger unit to a smaller unit, multiply. Going from a smaller unit to a bigger unit, divide. A quick check: converting to a smaller unit should give more units.

• 3 quarts to cups: 1 quart = 2 pints = 4 cups, so 3 × 4 = 12 cups.
• 2.5 kilometers to meters: 2.5 × 1,000 = 2,500 m.
• 750 milliliters to liters: 750 ÷ 1,000 = 0.75 L.

Mixed units. Convert everything to the smallest unit, compute, then convert back. A rope 7 ft 8 in long is cut into 4 equal pieces. First, 7 × 12 + 8 = 92 inches. Then 92 ÷ 4 = 23 inches, which is 1 ft 11 in.

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Money

• Line up the decimal points when adding or subtracting amounts. $4.05 + $12.6 means $4.05 + $12.60 = $16.65.
• Making change. Count up from the price. For a $7.35 purchase paid with $20: $7.35 → $7.40 (5¢) → $8.00 (60¢) → $10.00 ($2) → $20.00 ($10). The change is $12.65.
• Unit prices. To compare deals, divide price by quantity. 12 ounces for $3.00 is $0.25 per ounce. 20 ounces for $4.40 is $0.22 per ounce, so the larger package is cheaper per ounce.
• Cents and dollars. 45 cents is $0.45, not $45. Many distractors are off by a factor of 100.

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A Fixed Checking Order for Speed

1. Read the unit in the question. Hours or minutes? Inches or feet? Dollars or cents?
2. Compare or convert from the largest unit to the smallest: years before months before days, or hours before minutes.
3. Estimate before calculating. If a duration must be "a bit over 4 hours," reject 3 h 35 min and 5 h 35 min at once.