Câu 1: The sum of all one digit numbers?
0 + 1 + 2 +3 + 4 + 5 + 6 + 7 + 8 +9 = 45

Câu 2: Which value is not equal to 4500? (45tens, 450tens, 45 hundred)
45tens

Câu 3: Which number below is the word form of 20 300?
20 thousands and 3 hundreds 

Câu 4: How many two digit odd numbers are there that are greater than 15?
17, 19, 21, 23,.....99
There are = (99-17) : 2 + 1= 42

Câu 5: Lily writers a number. It has the digit 5 in the thousands place and the digit 8 in the units place. Which of these numbers could Lily have written?
5 008

Câu 6: What is the smallest posible number that can be written using the digits 4, 7, 0, 6? (use each digit only once)
4067

Câu 7: If the sum of three consecutive natural numbers is less than 90, find the largest possible value of the largest natural number is?
30

Câu 8: How many multiples of 4 lie between 1000 and 2500?
1004;1008;1012;...2500
There are: (2500-1004) : 4 +1= 375
 

Câu 9: Read number: 35 206 :
thirty five thousands two hundreds and six

Câu 10: Jack finished the bicycle race with a time of 34152 seconds, Jane finished with a time of 34215 seconds, and Tina finished with a time of 34125 seconds. In what order did they finish the race?
Tina -> Jack -> jane

Câu 11: The The greatest odd number that can be formed by all the digit 1,2,0 and 8 is?
8201

Câu 12: A rectangle having length and breadth are 25cm and 8cm respectively. The perimeter of the rectangle?
66cm

Câu 13: Amy put 50 photographs into an online photo album. On each page she could fit eight photos. How many photos were on the last page?
2 photos

Câu 14: Bon is 5 years old. Ben’s age is 3 years more than the double of Bon’s age. Find the age of Ben?
5 x 2 + 3 = 13 (years old)

Câu 15: Which value is equal to 56 hundreds? (56000; 5600 tens; 560 tens; 56 units)
560 tens

Câu 16:What is the perimeter of  a square with side lengths of 205 cm?  
820 cm

Câu 17: What is the greatest 3-digit number whose digits total is 13?
940

Câu 18: Anna has a chocolate chip cookie recipe that makes 60 cookies and calls for 6cups of flour. If he only wants to make 40 cookies. How many cups of flour would he need?
4
Câu 19: A string of 5m35cm was cut into 5 equal parts. What’s the length of each part in cm?
  5m35cm= 535cm
535 : 5 = 107 (cm)