An investigation involving adding and subtracting sets of consecutive numbers. Lots to find out, lots to explore.
Choose any three by three square of dates on a calendar page...
Investigate how you can work out what day of the week your birthday will be on next year, and the year after...
Although we had lots of answers to this problem, very few of you explained your solutions carefully. Alistair from Histon and Impington Infant School sent us this solution:
Chris, Isobel, Wui Shen and Alex from Maadi British International School in Cairo noticed something else:
We thought about the problem and worked it out together first. When we had our answer we tried to work out how to get our first numbers.
Wui Shen said we could take 1 away from the tens column and + 1 to the units column.
Isobel said we could + the two numbers and find two numbers that equal the same number.
Jordan from London explained why Wui Shen's method works: