“Singapore Math Level 2A & 2B – Review 5: Mental Calculation and Money” helps young learners improve their mental math skills while also building a solid understanding of money. Through fun exercises and problem-solving, this review guides students in quickly performing calculations and handling real-life money situations, making math both practical and engaging for them.
Singapore Math Level 2A & 2B – Review 5: Mental Calculation and Money solution step by step
1. Write in numerals: ninety-nine dollars and nine cents.
Solution:
ninety-nine dollars and nine cents
= $99 + 9¢
= $99 + $0.09
= $99.09
2. Add 814 and 90 mentally.
Solution:
814 + 90’s mental calculation:
814 + 100 = 914
914 – 10 = 904
So, 814 + 90 = 904
3. $55.15 = ______ dollars and ____ cents.
Solution:
$55.15
= $55 + 15¢
= fifty-five dollars and fifteen cents.
4. How much money is shown below?
Solution:
$50+$1+$1+$5+$5+50¢+5¢
= $50 + (2×$1) + (2×$5) + (50¢+5¢)
= ($50 + $2 + $10) + 55¢
= $62 + 55¢
= $62 + $0.55
= $62.55
There are shown $62.55
5. Write $62.85 in cents.
Solution:
62.85×100 = 6285
So, $62.85 = 6285¢
6. Add 604 and 200 mentally.
Solution:
600 + 200 = 800
800 + 4 = 804
So, 604 + 200 = 804
7. Grace has $30.05. Jerome has $35.55.
(a) $___ is more than $____.
(b) ______ has more money.
Solution:
(a) $35.55 is more than $30.05.
(b) Jerome has more money.
8. Subtract 9 from 546 mentally.
Solution:
546 – 10 = 536
536 + 1 = 537
So, 546 – 9 = 537
9. Write 3,840¢ in dollars.
Solution:
3,840 ÷ 100 = 38.40
∵ 3,840¢ = $38.40
10. Subtract 60 from 743 mentally.
Solution:
743 – 100 = 643
643 + 40 = 683
∵ 743 – 60 = 683
11.
A purse costs _______.
Solution:
$10+$10+$5+$5+$5+$1+10¢
= (2×$10) + (3×$5) + $1+10¢
= $20 + $15 + $1 + 10¢
= $36.00 + $0.10
= $36.10
A purse costs $36.10
12. Uncle Sam pays $45 for a bouquet of roses. Uncle Rafael pays $42 for a bouquet of sunflowers.
(a) $_____ is less than $______.
(b) …….. pays more for the flowers.
Solution:
(a) 42, 45
(b) Uncle Sam
13. $100.10 = …… dollars and ……… cents
Solution:
one hundred, ten
14. Add 5 and 686 mentally.
Solution:
686 + 10 = 696
696 – 5 = 691
∵ 5+686=691
15. Subtract 400 from 712 mentally.
Solution:
700 – 400 = 300
300 + 12 = 312
∵ 712 – 400 = 312
16. Samantha saves $2 each day. How much money does Samantha save in a week/seven days?
Solution:
model of problem – 16
7 × $2 = $14
Samantha saves $14 in a week.
17. Emma bought a toy. She gave the shopkeeper $50 & received $2 in change. How much did the toy cost?
Solution:
model of problem – 17
$50 – $2 = $48
The toy cost $48.
18. Natasha bought a dress for $49. She bought a shirt for $35. How much dollar did Natasha spend in all?
Solution:
model of problem – 18
$49 + $35 = $84
She spent $84 in all.
19. Mrs. Alyssa gives some money to her 3 children. Each child receives $7. How much money does Mrs. Alyssa give to her children in all?
Solution:
model of problem – 19
3 × $7 = $21
Mrs. Alyssa gives $21 to his children in all.
20. Vera pays $60 for 6 geometry box. How much does each geometry box cost?
Solution:
model of problem – 20
$60 ÷ 6 = $10
Each geometry box costs $10.
