HKIMO 2020 Grade 3 National Final (Heat) Set 01

Find the missing number: $1,3,6,10,15,21,\underline{\phantom{00}},\ldots$

If 14 April 2020 is Tuesday, what day of the week is 1 February 2020?

A street is 900 m long. Trees are planted every 15 m. How many trees are planted along the street?

Editorial endpoint convention: one row of trees includes both ends of the 900 m segment. The original wording leaves the endpoint arrangement unstated.

According to the pattern below, what is the missing number?

How many asterisks are there in the 14th group?

Find $562+747+253+394+438+146$.

Find $960\div3+960\div6+960\div12+960\div24+960\div48$.

Fill the blank so the equation is correct: $\underline{\phantom{000}}\div4\times7-5=51$.

Find $57\times23+14\times46+15\times23$.

Find $13\div9+35\div9+6\div9$.

Define $a\otimes b=(a-b)\times(a+3\times b)$. Find $152\otimes16$.

Fill the three blanks with multiplication or addition signs to make the equation correct. Write the complete equation: $9\;\underline{\phantom{+}}\;6\;\underline{\phantom{+}}\;4\;\underline{\phantom{+}}\;8=47$.

A, B, C, D are distinct digits from 1 to 9. Find A in the column addition below.

The numbers form an arithmetic sequence. Find the sum of the 11th and 16th terms: $15,23,31,39,47,\ldots$

What is the difference between the largest and smallest 3-digit multiples of 26?

Source glossary correction: the English question says multiples of 26, but the Vietnamese vocabulary gloss mistakenly says divisible by 36. The full Vietnamese question here follows the English value 26.

How many squares are there in the figure below?

Anna stacks identical cubes as shown. At least how many squares can be seen when viewing from the right?

A pyramid has 48 faces. How many edges does it have?

A square of side 48 cm is cut into 64 squares of side 6 cm. What is the difference between the large square's perimeter and the sum of all 64 small perimeters?

How many rectangles in the figure contain the asterisk?