Page 105 - Start Up Mathematics_1

3 Fill in the blank boxes.

(a) 34 = 3 tens + 4 ones (b) 29 = tens + ones

(c) 46 = tens + ones (d) 70 = tens + ones

(e) 53 = tens + ones (f) 61 = tens + one

(g) 80 = tens + ones (h) 94 = tens + ones

(i) 3 = tens + ones (j) 14 = ten + ones

(k) 87 = tens + ones (l) 58 = tens + ones

Counting on Abacus

We count 2-digit numbers on an abacus by using rods O and T.

Rod O reads in ones. Rod T reads in tens.

Look at some more examples.
H T O
1. To show number 23 on the abacus, put 3 beads in rod

O and 2 beads in rod T .

23 = 2 tens + 3 ones

H T O
2. To show number 56 on the abacus, put 6 beads in rod

O and 5 beads in rod T .

56 = 5 tens + 6 ones

97