Investigation

Materials:

  • paper
  • pencil
  • 6 coins (or trace 6 small circles on paper and cut them out)

If I put three beads onto the tens/ones rods I could make the numbers 30, 3, 21 or 12.

4 sets of tens and ones rods with beads on them, 3 tens 0 ones, 0 tens, 3 ones, 2 tens, 1 one and 1 ten, 2 ones.

What if I had 4 beads?
Predict how many numbers you think I could make?
Try it. Can you find all the numbers I could make with 4 beads?

What if I had 6 beads?
Predict how many numbers you think I could make?
Try it. Can you find all the numbers I could make with 6 beads?

Hints and Possible Questions

You may want to draw a tens and ones rod and have your child use coins to represent the different numbers and record them or your child may want to draw all the possibilities like the example above.

It may be helpful to use a small piece of paper for each possibility so your child can move them around to look for patterns or a system for finding all the numbers.

What is the biggest number you could make?
What is the smallest number you could make?
How do you know you have found all the numbers?

Modifications

You could increase or decrease the number of beads.

Adapted from nrich.maths.org