EXPRESSION STATION
This expression means 20 times the sum of 15 and 5.
Answer:
20 × (15 + 5) = 400
Which symbol belongs in the box?
100 × 8 □ 25 × (4 × 9)
Answer:
<
Because 800 < 900.
Solve:
234 × 6
Answer:
1,404
If:
25 × 30 = 750
then what is:
2.5 × 30?
Answer:
75
A school buys 5 sandwiches for $4.60 each.
How much do the sandwiches cost?
Answer:
$23.00
Evaluate this expression:
(900 − 400) ÷ 5
Answer:
100
Which symbol belongs in the box?
48 × 12 □ 50 twelves − 3 twelves
Answer:
<
Because:
48 twelves = 576
47 twelves = 564
Use the standard algorithm to solve:
314 × 24
Answer:
7,536
Solve:
4.6 × 47
Answer:
216.2
A school buys 8 bags of chips for $1.25 each.
How much do the chips cost?
Answer:
$10.00
Write and evaluate an expression for 4 times the sum of 125 and 75.
Answer:
4 × (125 + 75) = 800
Which symbol belongs in the box?
24 × 36 □ 18 twenty-fours, doubled
Answer:
=
Both expressions equal 864.
Solve using the standard algorithm:
514 × 33
Answer:
16,962
Solve:
1.25 × 39
Answer:
48.75
A teacher buys 10 sandwiches for $4.60 each and 12 bags of chips for $1.25 each.
How much does the teacher spend altogether?
Answer:
$61.00
Evaluate:
10 × (250 + 45)
Answer:
2,950
Without completely calculating both sides, determine the symbol:
75 × 16 □ 25 × (3 × 16)
Answer:
=
Because 75 = 25 × 3, so both expressions have the same factors.
This multiplication problem has a zero in the ones place of one factor:
546 × 405
What is the product?
Answer:
221,130
Jeanne uses 1.5 yards of ribbon for each bow. She wants to make 84 bows.
How many yards of ribbon does she need?
Answer:
126 yards
Because:
1.5 × 84 = 126
For a field trip, a school buys:
How much does the school spend in all?
Answer:
$264.95
Evaluate:
(560 + 440) × 14
Answer:
14,000
A student says these expressions are equal:
48 × 19
50 × 19 − 2 × 19
Is the student correct? Explain how you know without multiplying all the way out.
Answer:
Yes, they are equal.
The second expression can be rewritten as:
(50 − 2) × 19 = 48 × 19
Challenge time! Solve:
708 × 604
Answer:
427,632
Jeanne needs 126 yards of ribbon. There are 3 feet in 1 yard, and ribbon costs 10¢ per foot.
How much will all the ribbon cost?
Answer:
$37.80
Reasoning:
126 yards × 3 = 378 feet
378 × $0.10 = $37.80
Jeanne makes bows. Each bow requires 1.5 yards of ribbon.
She makes 84 bows. A manufacturer wants to make 1,000 times as many bows.
Write an expression using an exponent to show how many yards of ribbon the manufacturer needs. Do not calculate the total.
Answer:
1.5 × 84 × 10³ yards