Rocket holds a stopwatch over the practice course. "Raven, your lap was 12.35 seconds. Mine was 12.4."
"Who was faster?" Raven asks. "What do you notice when you line up the points?"
"12.35 and 12.40," Rocket says. "35 hundredths is less than 40 hundredths. You were faster by 0.05 seconds."
Nova hovers between them. "Decimals are everywhere today," she says. "The tape, the stopwatch, the height chart."
"And the kits," Raven adds. "Twelve of them, packed by the greatest common factor."
Rocket points at the garage thermometer. The red line sits just under the 0. "What number is that?"
Nova hums. "That is next week. Below zero."
Times: a lap of 12.35 seconds against 12.4 seconds. Line up the points: 12.40 - 12.35 = 0.05 seconds apart.
Heights: a height chart reads 1.52 meters. That is 152 centimeters, the point moved two places.
Lengths: 2.5 meters of ribbon for each of 6 badges takes 2.5 × 6 = 15 meters.
Sharing: 7.5 meters of string in 0.5 meter pieces makes 7.5 ÷ 0.5 = 15 pieces.
Packing: equal kits, equal teams, equal rows of chairs all use the greatest common factor.
Repeating: two blinking lights, two timers, or two runners lapping at different speeds line up at the least common multiple.
Breaking a sum apart: 36 + 8 = 4 × (9 + 2) is the distributive property doing a job.
| Week review | True or false? |
|---|---|
| 1,500 ÷ 12 = 125 | ? |
| 12.75 + 8.4 = 21.15 | ? |
| 0.6 × 0.4 = 0.24 | ? |
| The greatest common factor of 36 and 48 is 6. | ? |
| The least common multiple of 6 and 8 is 24. | ? |
A full week of decimals and factors. Tomorrow is Data Day: measure a room with your family.