Consecutive sums
Every odd number splits in two
An odd number is one more than twice something, so split it into halves differing by one.
Shared by a Veda teacher · Generated with Veda AI · Oct 2026
Veda Bites are swipeable micro-lessons — each one teaches exactly one idea. Here's a taste from this kit; the app has the full deck.
Every odd number splits in two
An odd number is one more than twice something, so split it into halves differing by one.
Some numbers have several forms
Twenty-one is 10 plus 11, and also 6 plus 7 plus 8, and also 1 up to 6.
The numbers that refuse
Try to write 8, 16 or 32 as a sum of consecutive numbers and you will fail.
Sometimes yes, sometimes no
Twenty plus 36 is 56, a multiple of 4. Twenty plus 14 is 34, which is not.
Even numbers come in two kinds
Divide an even number by 4 and the remainder is 0 or 2. It cannot be 1 or 3.
Two multiples of 4
Add 4p and 4q and take the 4 out: it is 4 times the quantity p plus q.
Put plus and minus signs between four numbers in all eight ways and every answer has the same parity. A short piece of algebra shows why, and the same reasoning tells you which expressions must come out even.
~35 min · full explanation, examples & memory tricks in the app
If a number divides two others, it divides their sum and their difference. The reverse is not safe. Sorting even numbers by the remainder they leave on 4 settles when two of them add to a multiple of 4.
~35 min · full explanation, examples & memory tricks in the app
Write a number by its place values and every shortcut explains itself. Each power of ten is one more than a multiple of nine. That is the whole secret of the digit sum, and a near miss of eleven gives that rule too.
~35 min · full explanation, examples & memory tricks in the app
105 questions laddered from warm-up to topper-level, each with an explanation. A taste:
Anshu writes 7 as 3 plus 4 and 12 as 3 plus 4 plus 5. Each of these is an example of a number written as
Beginnera sum of consecutive numbers
The numbers added run one after another with no gaps.
Split 9 into two whole numbers that follow one another. They are
Beginner4 and 5
Nine is one more than twice four, so the halves differ by one.
EVERY odd number splits into two whole numbers in a row. The reason is that an odd number is
Advancedone more than twice something
That extra one is what lets the two halves differ by one.
Of these forms, the one that does NOT add up to 21 is
Advanced4 plus 5 plus 6 plus 7
Those four numbers come to 22, while the other three forms all give 21.
51 flashcards in this kit — the app reviews them with spaced repetition so the right card returns on the right day.
Every game is built from this kit's own content — scores feed your mastery, so playing counts as studying.
The full Veda Bites deck, complete notes, spaced-repetition flashcards, leveled MCQs, tests and games for this kit — plus Daily Facts and the Arena, every day.