shawn wants to mode lthe number 13,450 using base ten blocks. how many large cubes, flats, and longs does he need to model the number?

A cube usually represents 1,000, a flat 100, and a long 10. Start with the largest value (1,000). You can use 13 cubes in 13,450, which gives you 13,000. The remainder is 450. This is less than 1,000 so move to the second largest - flats (100). Four flats give you 400, but since 50 is less than 100 we have to use the longs. We already have 13,400 (13 cubes plus 4 flats) so there is still 50 left. The longs represent ten, so five longs will make 50.

13 cubes are 13,000, 4 flats are 400, and 5 longs is 50. 13,000+400+50 = 13,450.

For problems like this, always start with the biggest option. Ask your self how many thousands are in the number. In this case, "thirteen thousand" is the correct answer. There are thirteen thousands, so you need 13 cubes.