7th Grade Math

8 Start Smart

If there are not enough decimal places in the product, you need to annex

zeros to the left.

Multiply Decimals

Multiply.

1.3 × 0.9

Estimate 1 × 1 = 1

1.3 1 decimal place

× 0.9 1 decimal place

1.17 2 decimal places

Check for Reasonableness 1.17 ≈ 1 

0.054 × 1.6

0.054 3 decimal places

× 1.6 1 decimal place

324

540

0.0864 Annex a zero on the left so the answer has four decimal places.

Check for Reasonableness 0.0864 ≈ 0 

Multiply.

b. 15.8 × 11 c. 88 × 2.5 d. 33 × 0.03

Everyday Use

Annex To attach to

something, as in a building

that is added to another

building.

Math Use

Annex To place a zero at

the beginning or end of a

decimal.

Place the decimal point in each product. Add zeros if necessary.

1. 1.32 × 4 = 528 2. 0.07 × 1.1 = 77 3. 0.4 × 0.7 = 28


2. 1.9 × 0.6 = 114 5. 1.4 × 0.09 = 126 6. 5.48 × 3.6 = 19728


3. INSECTS The graphic shows the
   How Fast Do Insects Fly?

(^) Insect Speed
(mph)
Dragonfly 15.6
Hornet 12.8
Bumblebee 6.4
nsects Fly?
peed
mph)
5. 6
2 .8
6. 4
speeds of three different insects.
a. At this speed, how far can a
bumblebee fly in 2 hours?
b. How far can a dragonfly fly in
3.5 hours?
c. How much farther can a hornet
fly in 3 hours than a bumblebee?
002_021_C00_SS_895130.indd 8 1/4/10 2:22 PM