Order numbers to three or more decimal places on a number line (including numbers greater than 1)
Closest to One
Timeframe: 10 min (warm-up activity)
Audience: Two players up to the whole class.
Materials: Pencil, paper, deck of playing cards with 10’s and picture cards removed.
Summary: Students draw a 3x3 grid. Each column of the grid represents tenths, hundredths and thousandths. Teacher randomly draws a card and the student places the number in any column of their choosing. Students should end up with 3 different 3-digit numbers. Students add all three numbers together to make a total. There are three variations you can play; make the smallest number, make the largest number, or (more difficult), see who can get closest to one whole. Once a number is written in place, it cannot be moved or changed.
Guiding questions: Can students do column method addition to add up the final total? If not, will they need a calculator? Students use skills such as estimating, rounding and probability of cards being drawn to attempt to make a number as close to one whole as possible. Student’s will use knowledge of place value, greater than and less than, to determine who wins and how much they win by.
Source: Henry Crofts