Estimate It
Round to estimate 48 x 21.
What is about 1,000 (50 x 20)
Area model for 34 x 12: what is the partial product 30 x 10?
300
23 x 14
322
A gym has 24 rows with 18 seats in each row. How many seats?
432 seats
Estimate 312 x 19.
what is about 6,000 (300 x 20)
Use partial products to find 24 x 15.
360 (200+100+40+20)
45 x 32
1,440
A bakery packs 36 cookies in a box and sells 25 boxes. How many cookies?
A bakery packs 36 cookies in a box and sells 25 boxes. How many cookies?
Is 29 x 413 closer to 1,200 or 12,000?
12,000 (30 x 400)
Use partial products to find 136 x 12.
1,632
214 x 25
5,350
A school orders 215 boxes of crayons with 24 crayons in each box. How many crayons?
5,160 crayons
A student says 487 x 52 = 2,532. Estimate to check. Is it reasonable?
No. The estimate is 25,000 (500 x 50)
47 x 23 has partial products 800, 120, and 21. What is the missing partial product, and what is the total?
140; total 1,081
358 x 46
16,468
A train has 47 cars. Each car holds 135 passengers. How many passengers can the train hold?
6,345 passengers