Here are some examples you could try:
Addtition
What happens when you add numbers ending in 9 to numbers ending in 3?
Investgate what happens when you add 2-digit palndromes such as 66+ 77 or 77+88+99
Investigate what happens when you add 3 consecutive numbers or 3 consecutive even numbers or 3 consecutive odd numbers:
Investigate what happens when you begin with any 3 digit number, reverse it and add to the orginal. Repeat until you have a palindrome.
Subtraction
Wht happens when:
- you subtract a number ending in 7 from a number ending in2?
- you subtract a number ending in 25 from a number ending in 26 eg 426-225?
- you subtract a number ending in 26 from a number ending in 25 eg 525-126?
Choose 3 different digits and form a number beginning with largest and finishing with smallest. Write the number in reverse and subtract eg 832-238. Now reverse the answer and add it to the answer, so
832-
238
594 +
495
1089
Try it!
Multiplication
Investigate what happens when you multiply:
- numbers ending in 4 by 6
- a number ending in 13 (113, 213) by 6
- 142857 by any single digit number up to 7
- a number ending in 7 by 13
Investigate the series: 11x18, 21x18, 31x18...
Investigate the multiples of 99
Decimals
Use a calculator to convert sevenths to a decimal 1/7=, 2/7=, 3/7= etc.
What do you notice?
Let me know if you want to borrow the book!
